#include <iostream>
using namespace std;
int pow[32];
int main(){
    pow[1] = 1;
    for(int i = 2; 32 > i; i++){
        pow[i] = pow[i-1]*2;
    }
    int n,k;cin>>n>>k;
    cout << pow[max(0,n-k+1)] << endl;
}