#include <stdio.h>
int factorial(int a){
    int b=1;
    while (a>1){
        b=b*a;
        a=a-1;
    }
    return b;
}
int P(int a,int b){
    if (a<b){
        int temp = b;
        b=a;
        a = temp;
    }
    return factorial(a)/factorial(a-b);
}
int main(){
    printf("%d", P(5,3));
    return 0;
}