#include<bits/stdc++.h>//submitRecord//
using namespace std;
//const int N=1e7+10;
int main(){
//freopen("","r",stdin);
//freopen("","w",stdout);
ios::sync_with_stdio();
cin.tie(nullptr);
cout.tie(nullptr);
double i;
int n,m;
cin>>m>>n;
i=pow(2,n)*1.0/pow(2,m);
printf("%.7lf",i);
//fclose(stdin);
//fclose(stdout);
return 0;
}
