#include "bits/stdc++.h"
#define in std::cin
#define out std::cout
#define rep(i,N) for(LL i=0;i<N;++i)
typedef long long int LL;

int main()
{
	LL N, K;
	in >> N >> K;

	LL min = (1LL << K), max = (1LL << N);
	LL ans = max / min - (min - 1) / min;
	out << ans << std::endl;
}