import java.util.Scanner;
public class Zuheshu {
//计算m阶乘
public static int Fun(int m){
int sum=0;
if( m < 0 )
System.out.println("input error,please input integer(bigger than 1):");
else if( m == 1 || m == 0 )
return 1;
else
sum = m * Fun(m-1);
return sum;
}
public static void main(String[] args) {
// TODO Auto-generated method stub
Scanner in = new Scanner(System.in);
int a,b,c,d;
System.out.println("Please input n :");
a = in.nextInt();
System.out.println("Please input k :");
b = in.nextInt();
c = Fun(a)/(Fun(b)*Fun(a-b));
System.out.print("Cnk=" + c);
d = Fun(a)/(Fun(b-1)*Fun(a-b+1)) + c;
System.out.print("Cn(k-1)=" + d);
}
}