#include <iostream>
#include <cstring>
using namespace std;

static const auto Initialize = [] {
    cin.sync_with_stdio(false); cin.tie(nullptr);
    return nullptr;
}();

int main() {
    int people, times, DP[30][30][31];
    while (cin >> people >> times) {
        memset(DP, 0, sizeof(DP));
        for (int i = 0; i < people; ++i)
            DP[i][(i + 1) % people][1] = DP[i][(i + people - 1) % people][1] = 1;
        for (int t = 2; t <= times; ++t) 
            for (int i = 0; i < people; ++i)
                for (int j = 0; j < people; ++j)
                    DP[i][j][t] = DP[(j + 1) % people][i][t - 1] + DP[(j + people - 1) % people][i][t - 1];
        cout << DP[0][0][times] << '\n';
    }
}