Problem:
Score : 100 points

Problem Statement

Takahashi has K 500-yen coins. (Yen is the currency of Japan.)
If these coins add up to X yen or more, print Yes; otherwise, print No.

Constraints

1 \leq K \leq 100

1 \leq X \leq 10^5

Input

Input is given from Standard Input in the following format:

K X

Output

If the coins add up to X yen or more, print Yes; otherwise, print No.

Sample Input 1

2 900

Sample Output 1

Yes

Two 500-yen coins add up to 1000 yen, which is not less than X = 900 yen.

Sample Input 2

1 501

Sample Output 2

No

One 500-yen coin is worth 500 yen, which is less than X = 501 yen.

Sample Input 3

4 2000

Sample Output 3

Yes

Four 500-yen coins add up to 2000 yen, which is not less than X = 2000 yen.

Solution in C++14 (GCC 5.4.1) (judge verdict: Wrong Answer)

#include <stdio.h>
#include <stdlib.h>
#include <string.h>

int main(){
   int N;
   char S[51],S2[51];
   int flag = 0, ans = 0;
   scanf("%d\n",&N);
   for(int i = 0;i < N;i++){
      if(flag == 4)
         flag = 0;
      scanf("%c",&S[i]);
      if((S[i] == 'A') && (flag == 0))
         flag++;
      else if((S[i] == 'A') && (flag == 1));
      else if((S[i] == 'B') && (flag == 1))
         flag++;
      else if((S[i] == 'C') && (flag == 2))
         flag++;
      else 
         flag = 0;
      if(flag == 3){
         ans++;
         flag++;
      }
      //printf("i=%d:Debag:%c:%d\n",i,S[i],flag);
   }
   printf("%d\n",ans);
   return 0;
}