View Code of Problem 120

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

int main()
{
    int h1,m1,h2,m2;

    while(scanf("%d:%d",&h1,&m1) != EOF)
    {
        scanf("%d:%d",&h2,&m2);
        int i,j,k = 0;
        for(i = h1*60+m1;i <= h2*60+m2;i++)
        {
            int h,m,s,flag = 0;
            h = i/60;
            m = i%60;
            s = h*2500+m;
            for(j = 2;j <= sqrt(s);j++)
            {
                if(s%j == 0)
                {
                    flag = 1;
                    break;
                }
            }
            if(!flag)
                k++;
        }
        printf("%d\n",k);
    }
}