View Code of Problem 120

#include<iostream>
#include<cstdio>
#include<cstring>
#include<algorithm>
#include<cctype>
#include<vector>
#include<cmath>
using namespace std;
bool is_sushu(int n){
	if(n==1)
		return false;
	for(int i=2;i<=sqrt(n);i++){
		if(n%i==0)
			return false;
	}
	return true;
}
int main(void){
	int h1, h2, m1, m2;
	while (scanf("%d:%d %d:%d",&h1,&m1,&h2,&m2) != EOF)
	{
		int n = 0;
		int sum1 = h1 * 2500 + m1;
		int sum2 = h2 * 2500 + m2;
		while (sum1 <= sum2)
		{
			if (is_sushu(sum1))
				n++;
			m1++;
			if (m1 == 60) 
			{
				m1 = 0;
				h1 = h1 + 1;
			}
			sum1 = h1 * 2500 + m1;
		}
		printf("%d\n",n);
	}
	return 0;
}