#include <cstdio>
#include <cstdlib>
#include <cstring>
#include <cmath>
#include <map>
#include <vector>
#include <queue>
#include <algorithm>

using namespace std;

//typedef pair<int,int> P;



int main(){
	int a;
	int b;
	char S[100];
	char num[100];
	double utc;

	scanf("%d %d %s", &a, &b, S);

	strncpy(num, S+4, strlen(S)-4);
	sscanf(num,"%lf", &utc);
	if(S[3]=='-') utc *= -1;

	utc -= 9;

	int m = b + (int)(60*utc);
	int h = a;

	if(m < 0){
		m += 60;
		h -= 1;
	}
	h += m/60;

	m %= 60;

	if(h<0) h+= 24;
	h %= 24;

	printf("%02d:%02d\n", h, m);

	return 0;
}