#define _USE_MATH_DEFINES
#include "bits/stdc++.h"
using namespace std;
#define FOR(i,j,k) for(int (i)=(j);(i)<(int)(k);++(i))
#define rep(i,j) FOR(i,0,j)
#define each(x,y) for(auto &(x):(y))
#define mp make_pair
#define MT make_tuple
#define all(x) (x).begin(),(x).end()
#define debug(x) cout<<#x<<": "<<(x)<<endl
#define smax(x,y) (x)=max((x),(y))
#define smin(x,y) (x)=min((x),(y))
#define MEM(x,y) memset((x),(y),sizeof (x))
#define sz(x) (int)(x).size()
#define RT return
#define vv(a,b,c,d) vector<vector<a> >(b,vector<a>(c,d))
#define vvv(a,b,c,d,e) vector<vector<vector<a> > >(b,vv(a,c,d,e))
using ll = long long;
using pii = pair<int, int>;
using vi = vector<int>;
using vll = vector<ll>;

int main() {
    //ios::sync_with_stdio(false);
    //cin.tie(0);
    //cout << fixed << setprecision(20);
    int a, b;
    string s;
    int M = 24 * 60;
    while (cin >> a >> b >> s) {
        a = (24 + a - 9) % 24;
        int t = a * 60 + b;
        int sgn = 1, dot = 0;
        each(c, s) {
            if (c == '-')sgn = -1;
            if (c == '.')dot = 1;
            if (!isdigit(c)) {
                c = ' ';
            }
        }
        stringstream ss(s);
        int dt = 0;
        ss >> s;
        dt = stoi(s) * 60;
        if (dot) {
            ss >> s;
            dt += stoi(s) * 6;
        }
        dt *= sgn;
        int now = (t + dt + M) % M;
        printf("%02d:%02d\n", now / 60, now % 60);
    }
}