Kombinasi

import java.util.Scanner;

public class Kombinasi {
    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);
        int n = scanner.nextInt();
        int x = scanner.nextInt();
        System.out.println(kombinasi(n,x));
    }
    public static int faktorial(int a){
        if (a==1)return 1;
        return a*faktorial(a-1);
    }
    public static int kombinasi(int a,int b){
        return faktorial(a)/(faktorial(b)*faktorial(a-b));
    }
}