George woke up and saw the current time *s* on the digital clock. Besides, George knows that he has slept for time *t*. 

Help George! Write a program that will, given time *s* and *t*, determine the time *p* when George went to bed. Note that George could have gone to bed yesterday relatively to the current time (see the second test sample).
The first line contains current time *s* as a string in the format "hh:mm". The second line contains time *t* in the format "hh:mm" — the duration of George's sleep. It is guaranteed that the input contains the correct time in the 24-hour format, that is, 00 ≤ *hh* ≤ 23, 00 ≤ *mm* ≤ 59.
#include<cstdio>
#include<cmath>
#include<string>
#include<iostream> 
using namespace std;
int main(){
	string a,b;
	char h[2]={'0','0'},m[2]={'0','0'};
	cin>>a>>b;
	int p;
	int s1,s2;
	s1=600*(a[0]-48)+60*(a[1]-48)+10*(a[3]-48)+a[4]-48;
    s2=600*(b[0]-48)+60*(b[1]-48)+10*(b[3]-48)+b[4]-48;
	p=s1-s2;
	printf("%c",p/600+48);
    p%=600;
    printf("%c",p/60+48);
    p%=60;
    printf(":");
    printf("%c",p/10+48);
    p%=10;
    printf("%c",p+48);
    return 0; 
} 