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

int main() {
    string s1, s2;
    cin >> s1 >> s2;
    int A = 10 * (s1[0] - '0') + s1[1] - '0';
    int B = 10 * (s2[0] - '0') + s2[1] - '0';
    int t = 60 * 60 * A + B * 60;
    double t1 = 6 * B;
    double t2 = (30 * A) % 360 + (double)B / 2;
    while (abs(t1 - t2) > 0.026) {
        t++;
        double s = t % 60;
        double m = (t / 60) % 60;
        int h = (t / 3600) % 12;
        t1 = 6 * m + s / 10.0;
        t2 = (30 * h) % 360 + m / 2.0 + s / 120.0;
    }
    cout << t - (3600 * A + 60 * B) << "\n";
    return 0;
}