#include <bits/stdc++.h>
using namespace std;

#define int long long
#define rep(i,l,r) for(int i=(int)(l);i<(int)(r);i++)
#define all(x) (x).begin(),(x).end()
#define pb push_back
template<class T>bool chmax(T &a,T b){if(a<b){a=b;return 1;}return 0;}
template<class T>bool chmin(T &a,T b){if(a>b){a=b;return 1;}return 0;}

typedef pair<int, int> pii;
typedef vector<int> vi;
typedef vector<vi> vvi;

const int inf = 1LL<<60;
const int mod = 1e9 + 7;
const double eps = 1e-9;

/*{
}*/

signed main()
{
  const int oneday = 60*24;

  int h, m;
  string s;
  cin >> h >> m >> s;

  int jp = (60*h+m - 60*9 + oneday)%oneday;
  double st = stof(s.substr(3, s.size()-3));
  int ans = (int)round(jp + st*60 + oneday)%oneday;

  printf("%02d:%02d\n", ans/60, ans%60);

  return 0;
}