import std.stdio, std.string, std.conv, std.algorithm;
import std.range, std.array, std.container, std.math, std.typecons;

void main() {
    auto s = readln.chomp;
    int min = timetomin(s) + 5;
    min %= 1440;
    mintotime(min).writeln;
}

int timetomin(string s) {
    auto hm = s.split(':').to!(int[]);
    return hm[0] * 60 + hm[1];
}

string mintotime(int min)
    in {
        assert(0 <= min && min < 1440);
    }

    body {
        return "%02s:%02s".format(min / 60, min % 60);
    }


void scan(T...)(ref T args) {
    auto line = readln.split;
    foreach (ref arg; args) {
        arg = line.front.to!(typeof(arg));
        line.popFront;
    }
    assert(line.empty);
}