OJ Board

Here is my Code. I have been tired seeing WA. Can anyone find the BUG ? Thanx In advance.

#include<stdio.h>
#include<math.h>

int a,j,m,k=0,i,n,c1,c2,flag2,prime[1000],flag[1000],count,left,right;
int main()

{

while(scanf("%d %d",&n,&c1)==2)
{

printf("%d %d: ",n,c1);
if((n < 1 || n > 1000 ...