It seems that Borya is seriously sick. He is going visit n doctors to find out the exact diagnosis. Each of the doctors needs the information about all previous visits, so Borya has to visit them in the prescribed order (i.e. Borya should first visit doctor 1, then doctor 2, then doctor 3 and so on). Borya will get the information about his health from the last doctor.

Doctors have a strange working schedule. The doctor i goes to work on the si-th day and works every di day. So, he works on days si, si + di, si + 2di, ....

The doctor's appointment takes quite a long time, so Borya can not see more than one doctor per day. What is the minimum time he needs to visit all doctors?

Input

First line contains an integer n — number of doctors (1 ≤ n ≤ 1000). 

Next n lines contain two numbers si and di (1 ≤ si, di ≤ 1000).

Output

Output a single integer — the minimum day at which Borya can visit the last doctor.

Examples

Input

3
2 2
1 2
2 2


Output

4


Input

2
10 1
6 5


Output

11

Note

In the first sample case, Borya can visit all doctors on days 2, 3 and 4.

In the second sample case, Borya can visit all doctors on days 10 and 11.
	
	
	 
	    	        			/*
	 * Author- Priyam Vora
	 * BTech 2nd Year DAIICT
	 */
	     
	     
	        		    import java.awt.Checkbox;
	import java.awt.Point;
	import java.awt.event.PaintEvent;
	import java.io.*;
	        		    import java.math.*;
	        		    import java.util.*;
	import java.util.Map.Entry;
	
	import javax.print.attribute.SetOfIntegerSyntax;
	import javax.swing.plaf.FontUIResource;
	    	     
	        		    public class Practice{
	        		  	private static InputStream stream;
	        		    	private static byte[] buf = new byte[1024];
	        		    	private static int curChar;
	        		    	private static int numChars;
	        		    	private static SpaceCharFilter filter;
	        		    	private static PrintWriter pw;
	        		    	private static long count = 0;
							static long mod=1000000007;
	        		    //	private static TreeSet<Integer> ts=new TreeSet[200000];
	public final static int INF = (int) 1E9;
	
	public static void main(String args[]) {
		InputReader(System.in);
		pw = new PrintWriter(System.out); 
	    new Thread(null ,new Runnable(){
	       public void run(){
	           try{
	               solve();
	               
	               pw.close();
	           } catch(Exception e){
	               e.printStackTrace();
	           }
	       }
	   },"1",1<<26).start();
	   }
	    static StringBuilder sb;
	    public static void test(){
	    	 sb=new StringBuilder();
	    	int t=nextInt();
	    	while(t-->0){
	    		
	    		solve();
	    		//pw.println();
	    		//sb.append("\n");
	    	}
	    	pw.println(sb);
	    }
	    public static long pow(long n, long p,long mod) {
			if(p==0)
				return 1;
			if(p==1)
				return n%mod;
			if(p%2==0){
				long temp=pow(n, p/2,mod);
			return (temp*temp)%mod;
			}else{
				 	long temp=pow(n,p/2,mod);
				 	temp=(temp*temp)%mod;
				 	return(temp*n)%mod;
				 	
			}
		}
	    public static long pow(long n, long p) {
			if(p==0)
				return 1;
			if(p==1)
				return n;
			if(p%2==0){
				long temp=pow(n, p/2);
			return (temp*temp);
			}else{
				 	long temp=pow(n,p/2);
				 	temp=(temp*temp);
				 	return(temp*n);
				 	
			}
		}
	    public static void Merge(long a[],int p,int r){
	        if(p<r){
	            int q = (p+r)/2;
	            Merge(a,p,q);
	            Merge(a,q+1,r);
	            Merge_Array(a,p,q,r);
	        }
	    }
	    public static void Merge_Array(long a[],int p,int q,int r){
	       long b[] = new long[q-p+1];
	        long c[] = new long[r-q];
	        for(int i=0;i<b.length;i++)
	            b[i] = a[p+i];
	        for(int i=0;i<c.length;i++)
	            c[i] = a[q+i+1];
	        int i = 0,j = 0;
	        for(int k=p;k<=r;k++){
	            if(i==b.length){
	                a[k] = c[j];
	                j++;
	            }
	            else if(j==c.length){
	                a[k] = b[i];
	                i++;
	            }
	            else if(b[i]<c[j]){
	                a[k] = b[i];
	                i++;
	            }
	            else{
	                a[k] = c[j];
	                j++;
	            }
	    
	        }
	    }
	    
	  
		public static long gcd(long x, long y) {
			if (x == 0)
				return y;
			else
				return gcd( y % x,x);
		}	
		
		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 LinkedList<Integer> adj[];
	        static boolean Visited[];
	        static HashSet<Integer> exc;
	        static long oddsum[]=new long[1000001];
	        static long co=0,ans=0;
	    
	    	private static void buildgraph(int n){
	    		adj=new LinkedList[n+1];
	    		Visited=new boolean[n+1];
	    		levl=new int[n+1];
	    		
	    		for(int i=0;i<=n;i++){
	    			adj[i]=new LinkedList<Integer>();
	    		
	    		}
	
	
	    	}
	      
	       
	        static int[] levl;
	        static int[] eat;
	        static int n,m;
	        static int price[];
	        //ind frog crab
	    
	        
	        static long d,x,y;
			static long modInverse(long A, long M)
			{
			extendedEuclid(A,M);
			return (x%M+M)%M;    //x may be negative
			}
			static void extendedEuclid(long A, long B) {
			if(B == 0) {
			d = A;
			x = 1;
			y = 0;
			}
			else {
			extendedEuclid(B, A%B);
			long temp = x;
			x = y;
			y = temp - (A/B)*y;
			}
			}
	        static double distance(int x1,int y1,int x2,int y2){
	        	return Math.sqrt((x1-x2)*(x1-x2) + (y1-y2)*(y1-y2));
	        }
	        static double area(int x1, int y1, int x2, int y2, int x3, int y3)
	        {
	           return Math.abs((x1*(y2-y3) + x2*(y3-y1)+ x3*(y1-y2))/2.0);
	        }
	        static boolean isInside(int x1, int y1, int x2, int y2, int x3, int y3, int x, int y)
	        {   
	           double A = area (x1, y1, x2, y2, x3, y3);
	         
	           double A1 = area (x, y, x2, y2, x3, y3);
	         
	           double A2 = area (x1, y1, x, y, x3, y3);
	         
	           double A3 = area (x1, y1, x2, y2, x, y);
	           
	          return (A == A1 + A2 + A3);
	        }
	      
			static int col[];
	    public static boolean isVowel(char c){
	    	if(c=='a' || c=='e'||c=='i' || c=='o' || c=='u')
	    		return true;
	    	return false;
	    }
	static Stack<Integer> st[];
	static Queue<Integer> q[];
	static long cost[];    
	 static final String S="0123456789";

	static long arr[];
	public static void solve(){

		int n=nextInt();
        long ans= 0;
        for(int i=0;i<n;i++) {
            long s=nextLong();
            long t=nextLong();
            if(s>ans) {
                ans=s;
            }else {
                ans= s+((ans-s)/t+1) *t;
            }
        }
        pw.println(ans);
		
	}
	private static long binomial(final int N, final int K) {

		BigInteger ret = BigInteger.ONE;
		for (int k = 0; k < K; k++) {
		    ret = ret.multiply(BigInteger.valueOf(N-k))
		             .divide(BigInteger.valueOf(k+1));
		}
		BigInteger mod2 = ret.mod(BigInteger.valueOf(mod));
		return mod2.longValue();

		}
	static long s_dynamic(int n,int k) {
	    int maxj = n-k;

	    arr = new long[maxj+1];

	    for (int i = 0; i <= maxj; ++i)
	        arr[i] = 1;

	    for (int i = 1; i <= k; ++i)
	        for(int j = 1; j <= maxj; ++j)
	            {
	        	arr[j] =(arr[j]%mod)+ (i%mod*(arr[j-1]%mod))%mod;
	        	arr[j]%=mod;
	            }

	    return arr[maxj];
	}
	 public static long factorial(long n) {
	        long a = 1;
	        for (long i = 1; i <= n; i++) a = (a%mod*i%mod)%mod;
	        return a;
	    }
	private static int  sum_dig(int j){
		String s=String.valueOf(j);
	int cnt=0;
		for(int i=0;i<s.length();i++){
			cnt+=(s.charAt(i)-'0');
		}
		return cnt;
		
	}
	static int no_vert=0;
	private static void dfs2(int s){
		Visited[s]=true;
		no_vert++;
		sb.append(s+" ");
		for(int x:pri[s]){
			if(!Visited[x]){
			
				dfs2(x);
			}
			
		}
	}
	
	private static void dfs4(int s){
		Visited[s]=true;
		no_vert++;
		sb.append(s+" ");
		for(int x:pri2[s]){
			if(!Visited[x]){
			
				dfs4(x);
			}
			
		}
	}
	
	    private static boolean Check(int x,int y,int n){
			if(x>=0 && x<n && y>=0 && y<n)
				return true;
			return false;
		}
	    
	    static long dp[],dp2[];
	    static ArrayList<Integer> pri[],pri2[];
	  private static void dfs(int curr,int par,int co){
		 Visited[curr]=true;
		 for(int x:adj[curr]){
			 if(!Visited[x]){
				 dfs(x,curr,co);
			 }
		 }
		 if(col[curr]==0){
			 dp[curr]++;
		 }else{
			 dp[curr]--;
		 }
		 if(dp[curr]>0){
			 pri[par].add(curr);
		 dp[par]+=dp[curr];
		 }
	  }
	  private static void dfs3(int curr,int par,int co){
			 Visited[curr]=true;
			 for(int x:adj[curr]){
				 if(!Visited[x]){
					 dfs3(x,curr,co);
				 }
			 }
			 if(col[curr]==1){
				 dp2[curr]++;
			 }else{
				 dp2[curr]--;
			 }
			 if(dp2[curr]>0){
				 pri2[par].add(curr);
			 dp2[par]+=dp2[curr];
			 }
		  }
	    public static String reverseString(String s) {
			StringBuilder sb = new StringBuilder(s);
			sb.reverse();
			return (sb.toString());
		}
	    
	  /*  
	   private static void BFS(int sou){
	    	Queue<Integer> q=new LinkedList<Integer>();
	    	q.add(sou);
	    	Visited[sou]=true;
	    	levl[sou]=0;
	    	while(!q.isEmpty()){
	    		int top=q.poll();
	    		
	    		for(int i:adj[top]){
	    			//pw.println(i+" "+top);
				if(!Visited[i])
				{
					
					q.add(i);
					levl[i]=levl[top]+1;
				}
				
				Visited[i]=true;
				
				}
			}
		}*/
		
	
	
	
	    		      static int indeg[];
	    		   /* private static void kahn(int n){
	    		    	
	    		    	PriorityQueue<Integer> q=new PriorityQueue<Integer>();
	    				for(int i=1;i<=n;i++){
	    					if(indeg[i]==0){
	    						q.add(i);
	    					}
	    				}
	    				while(!q.isEmpty()){
	    					int top=q.poll();
	    					st.push(top);
	    					for(Node i:adj[top]){
	    						indeg[i.to]--;
	    						if(indeg[i.to]==0){
	    							q.add(i.to);
	    						}
	    					}
	    				}
	    		    }
	    		        
	    		        static int state=1;
	    		        static long no_exc=0,no_vert=0;
	    		      static Stack<Integer> st;
	    		      static HashSet<Integer> inset;
	    		     /*   private static void topo(int curr){
	    		        	
	    		        	Visited[curr]=true;
	    		        	inset.add(curr);
	    		        	for(int x:adj[curr]){
	    		        		if(adj[x].contains(curr) || inset.contains(x)){
	    		        			state=0;
	    		        			return;
	    		        		}
	    		        		if(state==0)
	    		        			return;
	    		        		
	    		        	}
	    		        	st.push(curr);
	    		        	
	    		        	inset.remove(curr);
	    		        }*/
	    		        static HashSet<Integer> hs;
	    		       
	    		     
	    		     	static boolean prime[];
						static int spf[];
						public static void sieve(int n){
							prime=new boolean[n+1];
							spf=new int[n+1];
							
							Arrays.fill(spf, 1);
							Arrays.fill(prime, true);
						prime[1]=false;
							spf[2]=2;
							
						for(int i=4;i<=n;i+=2){
							spf[i]=2;
							prime[i]=false;
						}
						for(int i=3;i<=n;i+=2){
							if(prime[i]){
								spf[i]=i;
								for(int j=2*i;j<=n;j+=i){
									
									prime[j]=false;
								if(spf[j]==1){
									spf[j]=i;
								}
								}
							}
						}
						
							
						}
	    		     	
	    		    	// To Get Input
	// Some Buffer Methods
	 
	    		     	public static void sort(long a[]){
	    		     		Merge(a, 0, a.length-1);
	    		     	}
	    		    	public static void InputReader(InputStream stream1) {
	    		    		stream = stream1;
	    		    	}
	 
	    		    	private static boolean isWhitespace(int c) {
	    		    		return c == ' ' || c == '\n' || c == '\r' || c == '\t' || c == -1;
	    		    	}
	 
	    		    	private static boolean isEndOfLine(int c) {
	    		    		return c == '\n' || c == '\r' || c == -1;
	    		    	}
	 
	    		    	private static 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++];
	    		    	}
	 
	    		    	private static int nextInt() {
	    		    		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;
	    		    	}
	 
	    		    	private static long nextLong() {
	    		    		int c = read();
	    		    		while (isSpaceChar(c))
	    		    			c = read();
	    		    		int sgn = 1;
	    		    		if (c == '-') {
			sgn = -1;
			c = read();
		}
		long res = 0;
		do {
			if (c < '0' || c > '9')
				throw new InputMismatchException();
			res *= 10;
			res += c - '0';
	    		    			c = read();
	    		    		} while (!isSpaceChar(c));
	    		    		return res * sgn;
	    		    	}
	 
	    		    	private static String nextToken() {
	    		    		int c = read();
	    		    		while (isSpaceChar(c))
	    		    			c = read();
	    		    		StringBuilder res = new StringBuilder();
	    		    		do {
	    		    			res.appendCodePoint(c);
	    		    			c = read();
	    		    		} while (!isSpaceChar(c));
	    		    		return res.toString();
	    		    	}
	 
	    		    	private static String nextLine() {
	    		    		int c = read();
	    		    		while (isSpaceChar(c))
	    		    			c = read();
	    		    		StringBuilder res = new StringBuilder();
	    		    		do {
	    		    			res.appendCodePoint(c);
	    		    			c = read();
	    		    		} while (!isEndOfLine(c));
	    		    		return res.toString();
	    		    	}
	 
	    		    	private static int[] nextIntArray(int n) {
	    		    		int[] arr = new int[n];
	    		    		for (int i = 0; i < n; i++) {
	    		    			arr[i] = nextInt();
	    		    		}
	    		    		return arr;
	    		    	}
	 
	    		    	private static long[][] next2dArray(int n, int m) {
	    		    		long[][] arr = new long[n][m];
	    		    		for (int i = 0; i < n; i++) {
	    		    			for (int j = 0; j < m; j++) {
	    		    				arr[i][j] = nextLong();
	    		    			}
	    		    		}
	    		    		return arr;
	    		    	}
	    		    	private static char[][] nextCharArray(int n,int m){
	    		    		char [][]c=new char[n][m];
	    		    		for(int i=0;i<n;i++){
	    		    			String s[]=nextLine().split(" ");
	    		    			for(int j=0;j<s.length;j++){
	    		    				c[i][j]=s[j].charAt(0);
	    		    			}
	    		    		}
	    		    		return c;
	    		    	}
	 
	    		    	private static long[] nextLongArray(int n) {
	    		    		long[] arr = new long[n];
	    		    		for (int i = 0; i < n; i++) {
	    		    			arr[i] = nextLong();
	    		    		}
	    		    		return arr;
	    		    	}
	 
	    		    	private static void pArray(int[] arr) {
	    		    		for (int i = 0; i < arr.length; i++) {
	    		    			pw.print(arr[i] + " ");
	    		    		}
	    		    		pw.println();
	    		    		return;
	    		    	}
	 
	    		    	private static void pArray(long[] arr) {
	    		    		for (int i = 0; i < arr.length; i++) {
	    		    			pw.print(arr[i] + " ");
	    		    		}
	    		    		pw.println();
	    		    		return;
	    		    	}
	 
	    		    	private static void pArray(boolean[] arr) {
	    		    		for (int i = 0; i < arr.length; i++) {
	    		    			pw.print(arr[i] + " ");
	    		    		}
	    		    		pw.println();
	    		    		return;
	    		    	}
	 
	    		    	private static boolean isSpaceChar(int c) {
	    		    		if (filter != null)
	    		    			return filter.isSpaceChar(c);
	    		    		return isWhitespace(c);
	    		    	}
	 
	    		    	private interface SpaceCharFilter {
	    		    		public boolean isSpaceChar(int ch);
	    		    	}
	    		    	
	
	}
	
	    		
	