1010.cpp

#include <iostream>
using namespace std;

#define N_MAX   30
static int C[N_MAX+1][N_MAX+1];
int main(void) {
        cout.sync_with_stdio(false);
        cin.tie(nullptr);
        C[0][0] = 1;
        for (int i = 1; i <= N_MAX; ++i) {
                C[i][0] = C[i][i] = 1;
                for (int j = 1; j < i; ++j)
                        C[i][j] = C[i-1][j-1] + C[i-1][j];
        }

        int nTests;
        cin >> nTests;
        while (nTests--) {
                int n, m;
                cin >> n >> m;
                cout << C[m][n] << '\n';
        }
        return 0;
}