#include<bits/stdc++.h>
using namespace std;
int main(){
    int c,a,b;
    cin>>a>>b;
    c=a*(3.14*1.0*b*b);
    if(20/c*c<20){
        cout<<20/c+1;
    }else{
        cout<<20/c;
    }
    return 0;
}