#include <iostream>

using namespace std;

int main(){
    int a,b,t;
    cin>>a>>b;
    t=3600*a+b*60;
    int pa,pb;
    pa=t%(3600*12);
    pb=(t%3600)*12;
    int df=(pa-pb+3600*12)%(3600*12);
    cout<<df/11<<endl;
    
    return 0;
}