Leha is planning his journey from Moscow to Saratov. He hates trains, so he has decided to get from one city to another by car.

The path from Moscow to Saratov can be represented as a straight line (well, it's not that straight in reality, but in this problem we will consider it to be straight), and the distance between Moscow and Saratov is n km. Let's say that Moscow is situated at the point with coordinate 0 km, and Saratov — at coordinate n km.

Driving for a long time may be really difficult. Formally, if Leha has already covered i kilometers since he stopped to have a rest, he considers the difficulty of covering (i + 1)-th kilometer as a_{i + 1}. It is guaranteed that for every i ∈ [1, n - 1] a_i ≤ a_{i + 1}. The difficulty of the journey is denoted as the sum of difficulties of each kilometer in the journey.

Fortunately, there may be some rest sites between Moscow and Saratov. Every integer point from 1 to n - 1 may contain a rest site. When Leha enters a rest site, he may have a rest, and the next kilometer will have difficulty a_1, the kilometer after it — difficulty a_2, and so on.

For example, if n = 5 and there is a rest site in coordinate 2, the difficulty of journey will be 2a_1 + 2a_2 + a_3: the first kilometer will have difficulty a_1, the second one — a_2, then Leha will have a rest, and the third kilometer will have difficulty a_1, the fourth — a_2, and the last one — a_3. Another example: if n = 7 and there are rest sites in coordinates 1 and 5, the difficulty of Leha's journey is 3a_1 + 2a_2 + a_3 + a_4.

Leha doesn't know which integer points contain rest sites. So he has to consider every possible situation. Obviously, there are 2^{n - 1} different distributions of rest sites (two distributions are different if there exists some point x such that it contains a rest site in exactly one of these distributions). Leha considers all these distributions to be equiprobable. He wants to calculate p — the expected value of difficulty of his journey.

Obviously, p ⋅ 2^{n - 1} is an integer number. You have to calculate it modulo 998244353.

Input

The first line contains one number n (1 ≤ n ≤ 10^6) — the distance from Moscow to Saratov.

The second line contains n integer numbers a_1, a_2, ..., a_n (1 ≤ a_1 ≤ a_2 ≤ ... ≤ a_n ≤ 10^6), where a_i is the difficulty of i-th kilometer after Leha has rested.

Output

Print one number — p ⋅ 2^{n - 1}, taken modulo 998244353.

Examples

Input

2
1 2


Output

5


Input

4
1 3 3 7


Output

60
import java.util.*;
import org.omg.CORBA.INTERNAL;

import java.awt.List;
import java.io.*;
import java.lang.*;
import java.lang.reflect.Array;
	
public class code1
	{
	
		public static long[][] cnt;
		public static void main(String[] args)
		{
			InputReader in = new InputReader(System.in);
			PrintWriter pw = new PrintWriter(System.out);
			
			//Code starts..
		
			
			
			ArrayList<Long> list = new ArrayList<>();
			list.add(2L);
			list.add(6L);
			long mod = 998244353;
		int n = in.nextInt();
		long[] a = new long[n];
		for(int i=0; i<n; i++)
			a[i] = in.nextLong();
		
		
			
			for(int i=2; i<n; i++)
			{
				long a2 = list.get(i-1);
				long a1 = list.get(i-2);
				long tmp = ((a2-a1+mod)%mod*4L)%mod;
				list.add((tmp)%mod);
			}
			
			long sum = 0;
			for(int i=0; i<n; i++)
			{
				sum += (list.get(i)%mod * a[n-i-1]%mod)%mod;
				
			}
			
			long ans = sum %mod* (modInverse(2, mod));
			
			pw.println(ans%mod);
			
			
			
			//Code ends....
			
			pw.flush();
			pw.close();
		}
		  
		
		
		
	
		

		static class InputReader 
		{
			 
			private final InputStream stream;
			private final byte[] buf = new byte[8192];
			private int curChar, snumChars;
			private SpaceCharFilter filter;
	 
			public InputReader(InputStream stream) 
			{
				this.stream = stream;
			}
	 
			public int snext() 
			{
				if (snumChars == -1)
					throw new InputMismatchException();
				if (curChar >= snumChars) 
				{
					curChar = 0;
					try 
					{
						snumChars = stream.read(buf);
					} 
					catch (IOException e) 
					{
						throw new InputMismatchException();
					}
					if (snumChars <= 0)
						return -1;
				}
				return buf[curChar++];
			}
	 
			public int nextInt() 
		    {
				int c = snext();
				while (isSpaceChar(c)) 
				{
					c = snext();
				}
				int sgn = 1;
				if (c == '-')
			    {
					sgn = -1;
					c = snext();
				}
				int res = 0;
				do 
				{
					if (c < '0' || c > '9')
						throw new InputMismatchException();
					res *= 10;
					res += c - '0';
					c = snext();
				} while (!isSpaceChar(c));
				return res * sgn;
			}
	 
			public long nextLong()
		    {
				int c = snext();
				while (isSpaceChar(c)) 
				{
					c = snext();
				}
				int sgn = 1;
				if (c == '-') 
				{
					sgn = -1;
					c = snext();
				}
				long res = 0;
				do 
				{
					if (c < '0' || c > '9')
						throw new InputMismatchException();
					res *= 10;
					res += c - '0';
					c = snext();
				} while (!isSpaceChar(c));
				return res * sgn;
			}
	 
			public int[] nextIntArray(int n) 
			{
				int a[] = new int[n];
				for (int i = 0; i < n; i++) 
				{
					a[i] = nextInt();
				}
				return a;
			}
	 
			public String readString()
		    {
				int c = snext();
				while (isSpaceChar(c)) 
				{
					c = snext();
				}
				StringBuilder res = new StringBuilder();
				do 
				{
					res.appendCodePoint(c);
					c = snext();
				} while (!isSpaceChar(c));
				return res.toString();
			}
	 
			public String nextLine() 
			{
				int c = snext();
				while (isSpaceChar(c))
					c = snext();
				StringBuilder res = new StringBuilder();
				do 
				{
					res.appendCodePoint(c);
					c = snext();
				} while (!isEndOfLine(c));
				return res.toString();
			}
	 
			public boolean isSpaceChar(int c) 
			{
				if (filter != null)
					return filter.isSpaceChar(c);
				return c == ' ' || c == '\n' || c == '\r' || c == '\t' || c == -1;
			}
	 
			private boolean isEndOfLine(int c) 
			{
				return c == '\n' || c == '\r' || c == -1;
			}
	 
			public interface SpaceCharFilter
		    {
				public boolean isSpaceChar(int ch);
			}
		}
		public static long c = 0;
		
		public static long mod = 1000000007;
		public static int d;
		public static int p;
		public static int q;
		public static boolean flag;
		public static long INF= Long.MAX_VALUE;
		
		public static long fun(int[] a, int[] b, int m,int n) {
			long result =0;
			for(int i=0; i<m; i++)
				for(int j=0; j<m; j++)
				{
					long[] fib  = new long[Math.max(2, n+2)];
					fib[1] = a[i];
					fib[2] = b[j];
					for(int k=3; k<=n; k++)
						fib[k] = (fib[k-1]%mod + fib[k-2]%mod)%mod;
					result = (result%mod + fib[n]%mod)%mod;
				}
			
			return result;
			
		}
		
		
		public static double slope(pair p1, pair p2)
		{
			double m = INF;
			if((p1.x - p2.x)!=0)
			m =  (p1.y - p2.y)/(p1.x - p2.x); 
			
			
			return Math.abs(m);
			
		}
		
		
		public static int count(String[] s, int f)
		{
			int count = 0;
			int n = s[0].length();
			
			if(f==1)
			{
			for(int i = 0; i<n; i++)
			{
				for(int j=0; j<n; j++)
				{
					if(i%2==0)
					{
						if(j%2==0 && s[i].charAt(j)=='0')
							count++;
						if(j%2==1 && s[i].charAt(j)=='1')
							count++;
					}
					if(i%2==1)
					{
						if(j%2==1 && s[i].charAt(j)=='0')
							count++;
						if(j%2==0 && s[i].charAt(j)=='1')
							count++;
					}
					
				}
			}
			}
			else
			{
			
			 count = 0;
			
			for(int i = 0; i<n; i++)
			{
				for(int j=0; j<n; j++)
				{
					if(i%2==1)
					{
						if(j%2==0 && s[i].charAt(j)=='0')
							count++;
						if(j%2==1 && s[i].charAt(j)=='1')
							count++;
					}
					if(i%2==0)
					{
						if(j%2==1 && s[i].charAt(j)=='0')
							count++;
						if(j%2==0 && s[i].charAt(j)=='1')
							count++;
					}
					
				}
			}
 
			}	
				
		
			return count;
			
			
			
		}
				
		public static  int gcd(int p2, int p22)
		{
		    if (p2 == 0)
		        return (int) p22;
		    return gcd(p22%p2, p2);
		}
		
			
	
		
		
		public static int findGCD(int arr[], int n)
		{
		    int result = arr[0];
		    for (int i=1; i<n; i++)
		        result = gcd(arr[i], result);
		 
		    return result;
		}
		
	
 
		public static void nextGreater(long[] a, int[] ans)
		{
			
			Stack<Integer> stk = new Stack<>();
			stk.push(0);
			
			
			for(int i=1; i<a.length; i++)
			{
				
				if(!stk.isEmpty())
				{
				int s = stk.pop();
				while(a[s]<a[i])
				{
					ans[s] = i;
					if(!stk.isEmpty())
						s = stk.pop();
					else
						break;
				}
				if(a[s]>=a[i])
					stk.push(s);
				}
				
				stk.push(i);
				
			}
			return;
			
		}
		
		public static void nextGreaterRev(long[] a, int[] ans)
		{
			
			int n = a.length;
			int[] pans = new int[n];
			Arrays.fill(pans, -1);
			long[] arev = new long[n];
			for(int i=0; i<n; i++)
				arev[i] = a[n-1-i];
			
			Stack<Integer> stk = new Stack<>();
			stk.push(0);
			
			
			for(int i=1; i<n; i++)
			{
				
				if(!stk.isEmpty())
				{
				int s = stk.pop();
				while(arev[s]<arev[i])
				{
					pans[s] = n - i-1;
					if(!stk.isEmpty())
						s = stk.pop();
					else
						break;
				}
				if(arev[s]>=arev[i])
					stk.push(s);
				}
				
				stk.push(i);
				
			}
			
			//for(int i=0; i<n; i++)
				//System.out.print(pans[i]+" ");
			
			for(int i=0; i<n; i++)
				ans[i] = pans[n-i-1];
			
			
			
			return;
			
		}
		
		
		public static void nextSmaller(long[] a, int[] ans)
		{
			
			Stack<Integer> stk = new Stack<>();
			stk.push(0);
			
			
			for(int i=1; i<a.length; i++)
			{
				
				if(!stk.isEmpty())
				{
				int s = stk.pop();
				while(a[s]>a[i])
				{
					ans[s] = i;
					if(!stk.isEmpty())
						s = stk.pop();
					else
						break;
				}
				if(a[s]<=a[i])
					stk.push(s);
				}
				
				stk.push(i);
				
			}
			return;
			
		}
		
		
		
		
	    public static long lcm(int[] numbers) {
	        long lcm = 1;
	        int divisor = 2;
	        while (true) {
	            int cnt = 0;
	            boolean divisible = false;
	            for (int i = 0; i < numbers.length; i++) {
	                if (numbers[i] == 0) {
	                    return 0;
	                } else if (numbers[i] < 0) {
	                    numbers[i] = numbers[i] * (-1);
	                }
	                if (numbers[i] == 1) {
	                    cnt++;
	                }
	                if (numbers[i] % divisor == 0) {
	                    divisible = true;
	                    numbers[i] = numbers[i] / divisor;
	                }
	            }
	            if (divisible) {
	                lcm = lcm * divisor;
	            } else {
	                divisor++;
	            }
	            if (cnt == numbers.length) {
	                return lcm;
	            }
	        }
	    }
		public static long fact(long n) {
			
			long factorial = 1;
			 for(int i = 1; i <= n; i++)
		        {
		            factorial *= i;
		        }
			 return factorial;
		}
		
public static void factSieve(int[] a, int n) {
			
			
			for(int i=2; i<=n; i+=2)
				a[i] = 2;
			
			
			for(int i=3; i<=n; i+=2)
			{
				if(a[i]==0)
				{
					a[i] = i;
					
					for(int j=i; j*i<=n; j++)
					{
						a[i*j] = i;	
					}
				}
			}
			
			int k = 1000;
			while(k!=1)
			{
				System.out.print(a[k]+" ");
				k /= a[k];
				
			}
		}
	
		
		public static int lowerLimit(int[] a, int n) {
			int ans = 0;
			
			int ll = 0;
			int rl = a.length-1;
		//	System.out.println(a[rl]+" "+n);
			if(a[0]>n)
				return 0;
			if(a[0]==n)
				return 1;
			else if(a[rl]<=n)
				return rl+1;
		
			while(ll<=rl)
			{
				
				int mid = (ll+rl)/2;
				if(a[mid]==n)
				{
					ans = mid + 1;
					break;
				}
				
				else if(a[mid]>n)
				{
					rl = mid-1;
					
				}
				else
				{
					ans = mid+1;
					ll = mid+1;
				}
			}
			
			return ans; 
		}
		
		
		public static long choose(long total, long choose){
		    if(total < choose)
		        return 0;
		    if(choose == 0 || choose == total)
		        return 1;
		    return (choose(total-1,choose-1)+choose(total-1,choose))%mod;
		}
		
		public static int[] suffle(int[] a,Random gen)
		{
			int n = a.length;
			for(int i=0;i<n;i++)
			{
				int ind = gen.nextInt(n-i)+i;
				int temp = a[ind];
				a[ind] = a[i];
				a[i] = temp;
			}
			return a;
		}
		
		public static long[] sort(long[] a)
		{
			Random gen = new Random();
			int n = a.length;
			for(int i=0;i<n;i++)
			{
				int ind = gen.nextInt(n-i)+i;
				long temp = a[ind];
				a[ind] = a[i];
				a[i] = temp;
			}
			
			Arrays.sort(a);
			return a;
		}
		
		public static pair[] sort(pair[] a)
		{
			Random gen = new Random();
			int n = a.length;
			for(int i=0;i<n;i++)
			{
				int ind = gen.nextInt(n-i)+i;
				pair temp = a[ind];
				a[ind] = a[i];
				a[i] = temp;
			}
			
			Arrays.sort(a);
			return a;
		}
		
		
		public static int[] sort(int[] a)
		{
			Random gen = new Random();
			int n = a.length;
			for(int i=0;i<n;i++)
			{
				int ind = gen.nextInt(n-i)+i;
				int temp = a[ind];
				a[ind] = a[i];
				a[i] = temp;
			}
			
			Arrays.sort(a);
			return a;
		}
		
		public static int floorSearch(int arr[], int low, int high, int x)
		{
		    if (low > high)
		        return -1;
		 
		    if (x > arr[high])
		        return high;
		    int mid = (low+high)/2;
		 
		 
		    if (mid > 0 && arr[mid-1] < x && x < arr[mid])
		        return mid-1;
		 
		    if (x < arr[mid])
		        return floorSearch(arr, low, mid-1, x);
		 
		    return floorSearch(arr, mid+1, high, x);
		}
		
		
		public static void swap(int a, int b){
			int temp = a;
			a = b;
			b = temp;
		}
		public static ArrayList<Integer> primeFactorization(int n)
		{
			ArrayList<Integer> a =new ArrayList<Integer>();
			for(int i=2;i*i<=n;i++)
			{
				while(n%i==0)
				{
					a.add(i);
					n/=i;
				}
			}
			if(n!=1)
				a.add(n);
			return a;
		}
		
		
		public static void sieve(boolean[] isPrime,int n)
		{
			for(int i=1;i<n;i++)
				isPrime[i] = true;
			
			isPrime[0] = false;
			isPrime[1] = false;
			
			for(int i=2;i*i<n;i++)
			{
				if(isPrime[i] == true)
				{
					for(int j=(2*i);j<n;j+=i)
						isPrime[j] = false;
				}
			}
		}
		
		public static int lowerbound(ArrayList<Long> net, long c2) {
			int i=Collections.binarySearch(net, c2);
			if(i<0)
				i = -(i+2);
			return i;
			
			
		}
	
		public static int lowerboundArray(long[] psum, long c2) {
			int i=Arrays.binarySearch(psum, c2);
			if(i<0)
				i = -(i+2);
			return i;
			
			
		}
		
		public static int lowerboundArray(int[] psum, int c2) {
			int i=Arrays.binarySearch(psum, c2);
			if(i<0)
				i = -(i+2);
			return i;
			
			
		}
		
		
		public static int uperboundArray(long[] psum, long c2) {
			int i=Arrays.binarySearch(psum, c2);
			if(i<0)
				i = -(i+1);
			return i;
			
			
		}
		
		
		public static int uperbound(ArrayList<Long> net, long c2) {
			int i=Collections.binarySearch(net, c2);
			if(i<0)
				i = -(i+1);
			return i;
			
			
		}
		
		
		public static int GCD(int a,int b)
		{
			if(b==0)
				return a;
			else
				return GCD(b,a%b);
		}
		
		public static long GCD(long a,long b)
		{
			if(b==0)
				return a;
			else
				return GCD(b,a%b);
		}
		
		public static void extendedEuclid(int A,int B)
		{
			if(B==0)
			{
				d = A;
				p = 1 ;
				q = 0;
			}
			else
			{
				extendedEuclid(B, A%B);
				int temp = p;
				p = q;
				q = temp - (A/B)*q;
			}
		}
		
		public static long LCM(long a,long b)
		{
			return (a*b)/GCD(a,b);
		}
		
		public static int LCM(int a,int b)
		{
			return (a*b)/GCD(a,b);
		}
		
		public static int binaryExponentiation(int x,int n)
		{
		    int result=1;
		    while(n>0)
		    {
		        if(n % 2 ==1)
		            result=result * x;
		        x=x*x;
		        n=n/2;
		    }
		    return result;
		}
		
		
		public static int[] countDer(int n)
	    {
	        int der[] = new int[n + 1];
	     
	        der[0] = 1;
	        der[1] = 0;
	        der[2] = 1;
	     
	        for (int i = 3; i <= n; ++i)
	            der[i] = (i - 1) * (der[i - 1] + der[i - 2]);
	     
	        // Return result for n
	        return der;
	    }
		
		
		 static long binomialCoeff(int n, int k)
		    {
		    long C[][] = new long[n+1][k+1];
		    int i, j;
		     
		        // Calculate  value of Binomial Coefficient in bottom up manner
		    for (i = 0; i <= n; i++)
		    {
		        for (j = 0; j <= Math.min(i, k); j++)
		        {
		            // Base Cases
		            if (j == 0 || j == i)
		                C[i][j] = 1;
		      
		            // Calculate value using previosly stored values
		            else
		                C[i][j] = C[i-1][j-1] + C[i-1][j];
		          }
		     }
		      
		    return C[n][k];
		    }
		
		public static long binaryExponentiation(long x,long n)
		{
		    long result=1;
		    while(n>0)
		    {
		        if(n % 2 ==1)
		            result=result * x;
		        x=(x%mod * x%mod)%mod;
		        n=n/2;
		    }
		    return result;
		}
		
		public static int modularExponentiation(int x,int n,int M)
		{
		    int result=1;
		    while(n>0)
		    {
		        if(n % 2 ==1)
		            result=(result * x)%M;
		        x=(x%M*x%M)%M;
		        n=n/2;
		    }
		    return result;
		}
		
		public static long modularExponentiation(long x,long n,long M)
		{
		    long result=1;
		    while(n>0)
		    {
		        if(n % 2 ==1)
		            result=(result %M* x%M)%M;
		        x=(x*x)%M;
		        n=n/2;
		    }
		    return result;
		}
		
		public static int modInverse(int A,int M)
		{
		    return modularExponentiation(A,M-2,M);
		}
		
		public static long modInverse(long A,long M)
		{
		    return modularExponentiation(A,M-2,M);
		}
		
		
		public static boolean checkYear(int year)
	    {
			if (year % 400 == 0)
	            return true;
	     
	        if (year % 100 == 0)
	            return false;
	     
	        if (year % 4 == 0)
	            return true;
	        return false;
	    }
		
		public static boolean isPrime(int n)
		{
		    
		    if (n <= 1)  return false;
		    if (n <= 3)  return true;
		    
		    if (n%2 == 0 || n%3 == 0) 
		    	return false;
		 
		    for (int i=5; i*i<=n; i=i+6)
		    {
		        if (n%i == 0 || n%(i+2) == 0)
		           return false;
		    }
		    
		    return true;
		}
		
		static class pair implements Comparable<pair>

		{
			Long x, y;

			pair(long x, long y) {
				this.x = x;
				this.y = y;
			}

			public int compareTo(pair o) {
				int result = x.compareTo(o.x);
				if (result == 0)
					result = y.compareTo(o.y);

				return result;
			}

			public String toString() {
				return x + " " + y;
			}

			public boolean equals(Object o) {
				if (o instanceof pair) {
					pair p = (pair) o;
					if(p.x-x==0 && p.y-y==0)
						return true;
					else
					return false;
				}
				return false;
			}

			public int hashCode() {
				return new Long(x).hashCode() * 31 + new Long(y).hashCode();
			}

		}
		
		
		static class triplet implements Comparable<triplet>
		{
			Integer x,y;
			Long z;
			triplet(Integer l,Integer m,long z)
			{
				this.x = l;
				this.y = m;
				this.z = z;
			}
			
			public  int compareTo(triplet o)
			{
				int result = x.compareTo(o.x);
				if(result==0)
					result =  y.compareTo(o.y);
				if(result==0)
					result = z.compareTo(o.z);
 
				return result;
			}
			
			public boolean equlas(Object o)
			{
				if(o instanceof triplet)
				{
					triplet p = (triplet)o;
					return x==p.x && y==p.y && z==p.z;
				}
				return false;
			}
			
			public String toString()
			{
				return x+" "+y+" "+z;
			}
			public int hashCode()
			{
				return new Long(x).hashCode()*31 + new Long(y).hashCode() + new Long(z).hashCode(); 
			}
		}
		
		static class spair implements Comparable<spair>

		{
			String x;
			Integer y;

			spair(String x, int y) {
				this.x = x;
				this.y = y;
			}

			public int compareTo(spair o) {
				
				String s1 = x + o.x;
				String s2 = o.x + x;
				long p1 = cnt[y][0] + cnt[o.y][0];
				long p2 = p1;
				
				p1 += cnt[y][1] * cnt[o.y][2];
				p2 += cnt[o.y][1] * cnt[y][2];
				
				if(p1==p2)
						return 0;
				if(p1>p2)
					return -1;
				
				return 1;
				
				
				
				
			}

			public String toString() {
				return x + " " + y;
			}

			/*public boolean equals(Object o) {
				if (o instanceof pair) {
					pair p = (pair) o;
					return p.x == x && p.y == y;
				}
				return false;
			}

			public int hashCode() {
				return new Long(x).hashCode() * 31 + new Long(y).hashCode();
			}
			

		}

		
		
		
	
		/*static class node implements Comparable<node>
 
		{
			Integer x, y, z;
			node(int x,int y, int z)
			{
				this.x=x;
				this.y=y;
				this.z=z;
			}
			
			public int compareTo(pair o) {
				int result = x.compareTo(o.x);
				if(result==0)
					result = y.compareTo(o.y);
				if(result==0)
					result = z.compareTo(z); 
				return result;
			}
 
			@Override
			public int compareTo(node o) {
				// TODO Auto-generated method stub
				return 0;
			}  
		}
		*/
	}
	}
	
		