#include <iostream>
#include <string>

int main() {
    std::string a;
    std::cin >> a;
    int minute = (a[0] - '0') * 10 + (a[1] - '0') * 60 + (a[3] - '0') * 10 + (a[4] - '0');
    std::cin >> a;
    int real_minute = (a[0] - '0') * 10 + (a[1] - '0') * 60 + (a[3] - '0') * 10 + (a[4] - '0');

    int real = real_minute - minute;

    if (real > 0) {
        std::cout << real / 60 << real % 60 << std::endl;
    } else if (real < 0) {
        std::cout << (1440 + real) / 60 << (1440 + real) % 60 << std::endl;
    }

    return 0;
}