#include <bits/stdc++.h>
#define rep(i,n) for(int i = 0; i < (n); ++i)
#define srep(i,s,t) for (int i = s; i < t; ++i)
#define drep(i,n) for(int i = (n)-1; i >= 0; --i)
using namespace std;
typedef long long int ll;
typedef pair<int,int> P;
#define yn {puts("Yes");}else{puts("No");}
#define MAX_N 200005

int main() {
    int n, k;
    cin >> n >> k;
    k--;
    int m = (1 << n);
    int ans = 0;

    rep(i,m){
        int ii = i;
        int f[n] = {};
        rep(j,n){
            f[j] = ii % 2;
            ii /= 2;
        }
        if(f[k] == 1)continue;
        int mi0 = 1001001001;
        int mi1 = 1001001001;
        int ma0 = -1;
        int ma1 = -1;
        rep(j,n){
            if(f[j] == 0){
                mi0 = min(mi0, j);
                ma0 = max(ma0, j);
            }else{
                mi1 = min(mi1, j);
                ma1 = max(ma1, j);
            }
        }
        if(mi0 != k)continue;
        if(ma0 < mi1)continue;
        ans++;
    }

    cout << ans << endl;
    return 0;
}