boj1010.java

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.util.StringTokenizer;

public class boj1010 {

    static int[][] dp = new int[30][30];

    public static void main(String[] args) throws IOException {
        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
        StringBuilder sb = new StringBuilder();
        StringTokenizer st;

        int T = Integer.parseInt(br.readLine());

        for (int i = 0; i < T; i++) {
            st = new StringTokenizer(br.readLine());

            int N = Integer.parseInt(st.nextToken());
            int M = Integer.parseInt(st.nextToken());

            sb.append(comb(M, N)).append('\n');
        }

        System.out.println(sb);
    }

    static int comb(int n, int m) {

        if (dp[n][m] > 0) {
            return dp[n][m];
        }

        if (n == m || m == 0) {
            return dp[n][m] = 1;
        }

        return dp[n][m] = comb(n - 1, m - 1) + comb(n - 1, m);
    }
}