#include<bits/stdc++.h>

using namespace std;

double s, v;
int t;

int main()
{
	cin >> s >> v; t = ceil(s / v);
	int h = 30 - t / 60, m = 110 - t % 60;
	h += m / 60, h %= 24, m %= 60;
	if(h < 10) cout << 0;
	cout << h << ':';
	if(m < 10) cout << 0;
	cout << m << endl;
}

288B（好数字）