Enough is enough. Too many times it happened that Vasya forgot to dispose of garbage and his apartment stank afterwards. Now he wants to create a garbage disposal plan and stick to it.

For each of next n days Vasya knows a_i — number of units of garbage he will produce on the i-th day. Each unit of garbage must be disposed of either on the day it was produced or on the next day. Vasya disposes of garbage by putting it inside a bag and dropping the bag into a garbage container. Each bag can contain up to k units of garbage. It is allowed to compose and drop multiple bags into a garbage container in a single day.

Being economical, Vasya wants to use as few bags as possible. You are to compute the minimum number of bags Vasya needs to dispose of all of his garbage for the given n days. No garbage should be left after the n-th day.

Input

The first line of the input contains two integers n and k (1 ≤ n ≤ 2⋅10^5, 1 ≤ k ≤ 10^9) — number of days to consider and bag's capacity. The second line contains n space separated integers a_i (0 ≤ a_i ≤ 10^9) — the number of units of garbage produced on the i-th day.

Output

Output a single integer — the minimum number of bags Vasya needs to dispose of all garbage. Each unit of garbage should be disposed on the day it was produced or on the next day. No garbage can be left after the n-th day. In a day it is allowed to compose and drop multiple bags.

Examples

Input

3 2
3 2 1


Output

3


Input

5 1
1000000000 1000000000 1000000000 1000000000 1000000000


Output

5000000000


Input

3 2
1 0 1


Output

2


Input

4 4
2 8 4 1


Output

4
import java.io.BufferedWriter;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.io.OutputStreamWriter;
import java.io.PrintWriter;
import java.io.Writer;
import java.util.Arrays;
import java.util.InputMismatchException;
import java.util.*;
import java.io.*;
import java.math.*;
public class Main
{
    public static long pow(long a, long b)
    {
        long result=1;
        while(b>0)
        {
            if (b % 2 != 0)
            {
                result=(result*a);
                b--;
            } 
            a=(a*a);
            b /= 2;
        }   
                return result;
    }
    public static BigInteger fact(long num)
    {
                BigInteger fact=new BigInteger("1");
                int i=0;
                for(i=1; i<=num; i++)
                {
                    BigInteger bg=BigInteger.valueOf(i);
                    fact=fact.multiply(bg);
                }
                return fact;
            }
            public static long gcd(long a, long b)
            {
                if (a == 0)
                    return b;
                return gcd(b%a, a);
            }
            
            public static long lcm(int a,int b)
            {
                return a * (b / gcd(a, b));
            }
            public static long sum(int h)
            {
                return (h*(h+1)/2);
            }
		/*	public static void dfs(int parent,boolean[] visited)
			{
				ArrayList<Integer> arr=new ArrayList<Integer>();
				arr=graph.get(parent);
				visited[parent]=true;
				storing1[parent]=count++;
				for(int i=0;i<arr.size();i++)
				{
					int num=arr.get(i);
					if(visited[num]==false)
					{
						dfs(num,visited);
					}
				}
				storing2[parent]=count;
			}
			static int count=0;
			static int[] storing1;
			static int[] storing2;
			static ArrayList<ArrayList<Integer>> graph;
		*/	public static void main(String args[])throws IOException
            {
                InputReader in=new InputReader(System.in);
        		OutputWriter out=new OutputWriter(System.out);
        	//	long a=pow(26,1000000005);
        	//    BufferedReader br=new BufferedReader(new InputStreamReader(System.in));
        	    ArrayList<Integer> ar=new ArrayList<>();
				ArrayList<Integer> ar1=new ArrayList<>();
				TreeSet<Integer> ts=new TreeSet<>();
				TreeSet<Integer> ts1=new TreeSet<>();
				HashMap<Integer,Integer> hash=new HashMap<Integer,Integer>();
				int n=i();
				int k=i();
				long[] a=new long[n];
				for(int i=0;i<n;i++)
				{
					a[i]=l();
				}
				long num1=0,num=0,count=0,bag=0;
				for(int i=0;i<n;i++)
				{
				//		System.out.println(num+" "+num1+" "+bag);
				
					if((num1+a[i])/k<1 && i!=0 && num1!=0)
					{
						if(num1==0 && a[i]==0)
						{
							//continue;
						}
						else
						{
							bag++;
							num1=0;
						//	continue;
						}
					}
					else
					{
						num=(long)((num1+a[i])/k);
						num1=(num1+a[i])%k;
						bag+=num;
					}
				}//	System.out.println(num+" "+num1+" "+bag);
				if(num1!=0)
					bag++;
				pln(bag+"");
			}
			
			
			
			/**/
			static InputReader in=new InputReader(System.in);
                static OutputWriter out=new OutputWriter(System.out);
                public static long l()
                {
                    String s=in.String();
                    return Long.parseLong(s);
                }
                public static void pln(String value)
                {
                    System.out.println(value);
                }
                public static int i()
                {
                    return in.Int();
                }
                public static String s()
                {
                    return in.String();
                }
	}
         
         
         
         
         
         
         
         
         
         
         
         
         
         
         
         
         
         
         
         
         
         
        class InputReader {
        	 
        	private InputStream stream;
        	private byte[] buf = new byte[1024];
        	private int curChar;
        	private int numChars;
        	private SpaceCharFilter filter;
         
        	public InputReader(InputStream stream) {
        		this.stream = stream;
        	}
         
        	public int read() {
        		if (numChars== -1)
        			throw new InputMismatchException();
        		if (curChar >= numChars) {
        			curChar = 0;
        			try {
        				numChars = stream.read(buf);
        			} catch (IOException e) {
        				throw new InputMismatchException();
        			}
        			if (numChars <= 0)
        				return -1;
        		}
        		return buf[curChar++];
        	}
         
        	public int Int() {
        		int c = read();
        		while (isSpaceChar(c))
        			c = read();
        		int sgn = 1;
        		if (c == '-') {
        			sgn = -1;
        			c = read();
        		}
        		int res = 0;
        		do {
        			if (c < '0' || c > '9')
        				throw new InputMismatchException();
        			res *= 10;
        			res += c - '0';
        			c = read();
        		} while (!isSpaceChar(c));
        		return res * sgn;
        	}
         
        	public String String() {
        		int c = read();
        		while (isSpaceChar(c))
        			c = read();
        		StringBuilder res = new StringBuilder();
        		do {
        			res.appendCodePoint(c);
        			c = read();
        		} while (!isSpaceChar(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;
        	}
         
        	public String next() {
        		return String();
        	}
         
        	public interface SpaceCharFilter {
        		public boolean isSpaceChar(int ch);
        	}
        }
         
        class OutputWriter {
        	private final PrintWriter writer;
         
        	public OutputWriter(OutputStream outputStream) {
        		writer = new PrintWriter(new BufferedWriter(new OutputStreamWriter(outputStream)));
        	}
         
        	public OutputWriter(Writer writer) {
        		this.writer = new PrintWriter(writer);
        	}
         
        	public void print(Object...objects) {
        		for (int i = 0; i < objects.length; i++) {
        			if (i != 0)
        				writer.print(' ');
        			writer.print(objects[i]);
        		}
        	}
         
        	public void printLine(Object...objects) {
        		print(objects);
        		writer.println();
        	}
         
        	public void close() {
        		writer.close();
        	}
         
        	public void flush() {
        		writer.flush();
        	}
         
        	}
         
            class IOUtils {
         
        	public static int[] readIntArray(InputReader in, int size) {
        		int[] array = new int[size];
        		for (int i = 0; i < size; i++)
        			array[i] = in.Int();
        		return array;
        	}
         
        	} 