View Code of Problem 120

#include<stdio.h>
#include<math.h>
int prime(int n){
	if(n==0||n==1)return 0;
	if(n==2)return 1;
	for(int i=2;i<=sqrt(n);i++){
		if(n%i==0){
			return 0;
			break;
		}
	}
	return 1;
}
int main(){
	int h1,m1,h2,m2,t1,t2,t,h,m,cout;
	while(scanf("%d:%d %d:%d",&h1,&m1,&h2,&m2)!=EOF){
		cout=0;
		t1=h1*60+m1;
		t2=h2*60+m2;
		t=t1;
		h=h1;
		m=m1;
		while(t>=t1&&t<=t2){
			if(prime(h*2500+m))cout++;
			t++;
			h=t/60;
			m=t%60;
		}
		printf("%d\n",cout);
	}
}