View Code of Problem 120

#include<iostream>
using namespace std;

int main(void){
	int h1,h2,m1,m2,s=0,a=0,b=0,flag=1,k,h,m;
	while(scanf("%d:%d%d:%d",&h1,&m1,&h2,&m2)!=EOF){
		k=0;
		a=h1*60+m1;
		b=h2*60+m2;
		for(int i=a;i<=b;i++){
			flag=1;
			h=i/60;
			m=i%60;
			s=h*2500+m;
			for(int j=2;j*j<=s;j++){
				if(s%j==0) flag=0;
			}
			if(flag==1) k++;
		}
		cout<<k<<endl;
	}
}