#include <stdio.h>

int arrnum(int n,int n1,int m)
{
    if(n+m-1==n1) return n;
    return n*arrnum(n-1,n1,m);
}
int main()
{
    int n,m;
    scanf("%d %d",&n,&m);
    int result=arrnum(n,n,m);
    printf("%d\n",result);
    return 0;
}