View Code of Problem 120

#include <stdio.h>
#include <cmath>
int prime(int x,int k){
	int m,i,N = 0;
	m = (int)sqrt(x);
	for(i = 2;i<=m;i++){
		if(x%i==0)
			N++;
	}
	if(N == 0)
		 k++;		
	return k;
}
main(){
	int h,m;
	while(scanf("%2d:%2d",&h,&m)!=EOF){
		int H,M,i,sum,N=0;
		scanf("%2d:%2d",&H,&M);
		sum = 60*(H-h)+(M-m);
		for(i =0;i<=sum;i++){
			if(m>=60){
				m = m-60;
				h++;
			}
			N = prime(h*2500+m,N);
			m++;
		}
		printf("%d\n",N);
	}
	return 0;
}