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

int main(){
    int a, b;
    cin >> a >> b;
    auto f=[&](int sec){
        int m = sec % 3600;
        int h = sec; 
        return (m * 12 <= h);
    };
    auto g=[&](int sec){
        int m = sec % 3600;
        int h = sec;
        cerr << h / 3600 << ":" << m / 60 << ' '; 
    };
    int ans = 7200;
    for(int i = 0; i < 7200; i++){
        int s1 = a * 3600 + b * 60 + i;
        s1 %= 43200;
        int s2 = a * 3600 + b * 60 + i + 1;
        s2 %= 43200;
        if(f(s1) && !f(s2))ans = min(ans ,i);
    }
    cout << ans << endl;
}