#include using namespace std; int main(){ int a,b; cin>>a>>b; int jiao=a*10+b; cout<<jiao/19; return 0; }

#include<iostream>
using namespace std;
int main(){
    int a,b;
    cin>>a>>b;
    int jiao=a*10+b;
    cout<<jiao/19;
    return 0;
}