include <iostream>

include <cstring>

include <cstring>

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';

}

}