#include <iostream>
#include <iomanip>
using namespace std;

int main(){
	int a, b;
	char c;
	cin >> a >> c >> b;
	if(60 <= (b += 5)){
		if(++a == 24) a = 0;
		b %= 60;
	}
	cout << setw(2) << setfill('0') << a << ':' << b << endl;
}