/* -*- coding: utf-8 -*-
 *
 * 652.cc: No.652 E869120 and TimeZone - yukicoder
 */

#include<cstdio>
#include<cstdlib>
#include<cstring>
#include<cmath>
#include<iostream>
#include<string>
#include<vector>
#include<map>
#include<set>
#include<stack>
#include<list>
#include<queue>
#include<deque>
#include<algorithm>
#include<numeric>
#include<utility>
#include<complex>
#include<functional>
 
using namespace std;

/* constant */

/* typedef */

/* global variables */

/* subroutines */

inline int readnum(string &s, int &pos) {
  while (pos < s.size() && (s[pos] < '0' || s[pos] > '9')) pos++;
  int num = 0;;
  while (pos < s.size() && s[pos] >= '0' && s[pos] <= '9')
    num = num * 10 + s[pos++] - '0';
  return num;
}

/* main */

int main() {
  int a, b;
  string stz;
  cin >> a >> b >> stz;

  int cm = (a - 9) * 60 + b;

  int sign = (stz[3] == '+') ? 1 : -1;
  int pos = 4;
  int tzh = readnum(stz, pos), tzm = 0;
  if (pos < stz.size() && stz[pos] == '.') {
    pos++;
    tzm = readnum(stz, pos) * 6;
  }

  int tm = sign * (tzh * 60 + tzm);
  int m = (cm + tm + 1440) % 1440;
  printf("%02d:%02d\n", m / 60, m % 60);
  return 0;
}