#include<bits/stdc++.h> using namespace std; int main(){ int nl=20,x,y,n=0; cin>>x>>y; while(nl>0){ nl-=x; if(nl<0) break; nl+=y; n++; } cout<<n; return 0; }

#include<iostream>
#include<algorithm>
using namespace std;
int main(){
int a=20,x,y,b=0;
cin>>x>>y;
while(a>0){
a-=x;
if(a<0)
break;
a+=y;
b++;
}
cout<<b;
return 0;
}