#include <stdio.h>
#include <math.h>

int main() {
    int hour, _hour, _minute, m, h, i;
    double minute, length, velocity;
    scanf("%lf %lf", &length, &velocity);
    h = (int) (length / velocity);
    hour = (h + 10) / 60;
    minute = (length / velocity + 10) - 60 * hour;
    m = (h + 10) - 60 * hour;
    if (m == 0 && (fabs)(minute - m) < 1e-3) {
        if (8 - hour >= 1) {
            i = 8 - hour;
        } else {
            i = 24 + (8 - hour) % 24;
        }
        _hour = i;

        _minute = (int) (60 - minute);
    } else if (m != 0 && (fabs)(minute - m) > 1e-3) {
        if (8 - hour - 1 >= 0) {
            i = 8 - hour - 1;
        } else {
            i = 24 - (8 - hour - 1) % 24;
        }
        _hour = i;

        _minute = (int) (60 - minute);
    } else {
        if (8 - hour >= 1) {
            i = 8 - hour - 1;
        } else {
            i = 24 + (8 - hour - 1) % 24;
        }

        _hour = i;
        _minute = (int) (60 - minute);

    }

    if (_minute == 60)
        _minute = 0;
    printf("%02d:%02d", _hour, _minute);
    return 0;
}