#include <iostream>
#include <vector>
#include <cmath>
#include <algorithm>
#include <string>
#include <queue>
#include <stack>
using namespace std;

int main(){
  int a, b,c = -9999;
  string s;
  cin >> a >> b >> s;
  int ina = a;
  int inb = b;

  int seisuu = -9999, syousuu = -9999;

  string left, right;

  s = s.substr(3);
  if (s.find('.') == string::npos) {
    seisuu = stoi(s) - 9;
    a += seisuu;
    if (a < 0) a = 24+a;
    else a = a%24;
    left = (to_string(a).length() == 1)? "0" + to_string(a): to_string(a);
    right = (to_string(b).length() == 1)? "0" + to_string(b): to_string(b);
    cout << left << ":"  <<  right << endl;
    return 0;
  }


  int pos = s.find('.');
  seisuu = stoi(s.substr(0, pos)) - 9;
  syousuu = stoi(s.substr(pos+1)) * 6;

  if (seisuu < 0) {
    a += seisuu;
    b = (b + syousuu)%60;
    if (a < 0) a = 24+a;
    else a = a%24;
    left = (to_string(a).length() == 1)? "0" + to_string(a): to_string(a);
    right = (to_string(b).length() == 1)? "0" + to_string(b): to_string(b);
    cout << left << ":"  <<  right << endl;
    return 0;
  }

  a = a + seisuu;
  b = b + syousuu;
  a += b/60;
  b = b%60;
  if (a < 0) a = 24+a;
  else a = a%24;
  left = (to_string(a).length() == 1)? "0" + to_string(a): to_string(a);
  right = (to_string(b).length() == 1)? "0" + to_string(b): to_string(b);
  cout << left << ":"  <<  right << endl;
}