079 : 다리 놓기

import java.util.Scanner;

public class Main {
    public static void main(String[] args) {

        // ISC
        Scanner sc = new Scanner(System.in);
        int tC = sc.nextInt();

        // D2F
        int[][] TP = new int[31][31];
        for (int i = 0; i <= 30; i++) {
            TP[i][1] = i;
            TP[i][0] = 1;
            TP[i][i] = 1;
        }

        // OP + OEC patch
        for (int i = 2; i <= 30; i++) {
            for (int j = 1; j < i; j++) {
                TP[i][j] = TP[i][j-1] + TP[i-1][j-1];
            }
        }
        for (int i = 1; i <= tC; i++) {
            int s = sc.nextInt();
            int e = sc.nextInt();
            System.out.println(TP[s][e]);
        }

    }
}