飞花的糖果(计算组合数)

import java.util.*;
class Cal{
	int n;
	int m;
	public Cal(int n,int m) {
		this.n=n;
		this.m=m;
	}
	int getNum() {
		int sum=1,t1=1,t2=1,t3=1;
		int i;
		for(i=n;i>=1;i--) {
			t1*=i;
		}
		for(i=m;i>=1;i--) {
			t2*=i;
		}
		for(i=n-m;i>=1;i--) {
			t3*=i;
		}
		sum=t1/(t2*t3);
		return sum;
	}
	
}

public class Main{
	public static void main(String[] args) {
		Scanner sc=new Scanner(System.in);
		while(sc.hasNext()) {
			int a=sc.nextInt();
			int b=sc.nextInt();
			Cal cal=new Cal(a,b);
			int sum=cal.getNum();
			System.out.println(sum);
		}
		sc.close();
	}
}