View Code of Problem 120

#include <stdio.h>
#include <math.h>
int isp(int n)
{
   if(n<=1) 
   return 0;
    int i;
   for(i=2;i<=sqrt(n);i++)
   {
     if(n%i==0) 
	   return 0;
    }
    return 1;
} 
int main()
{
	int h1,h2,m1,m2;
	while(scanf("%d:%d",&h1,&m1)!=EOF)
	{
		scanf("%d:%d",&h2,&m2);
		int c=0;
		while(h1<h2||m1<m2)
		{
			if(isp(m1+h1*2500))
				c++;
			m1++;
			if(m1==60)
			{
				m1=0;
				h1++;
			}
		}
		printf("%d\n",c);
	}
	return 0;
}