#include<bits/stdc++.h>
using namespace std;
typedef long long SL;
bool sg[33][202];
SL f[33][202];
int n,m;
int main() {
freopen("ionah.in","r",stdin);
freopen("ionah.out","w",stdout);
cin >> n >> m;
memset(f,127/3,sizeof f);
f[3][0] = 0;
for (int i = 1; i <= m; i++) f[3][i] = f[3][i-1]*2+1;
for (int i = 4; i <= n; i++) {
f[i][0] = 0; f[i][1] = 1;
for (int j = 2; j <= m; j++)
for (int k = 1; k <= j; k++)
f[i][j] = min(f[i][j],f[i][k]*2+f[i-1][j-k]);
}
cout << f[n][m];
return 0;
}