#include<stdio.h>

int main(){
	int n;
	scanf("%d",&n);
	int a[100]={1};
	int s[100]={};
	for(int i=1;i<=n;i++){
		for(int i1=0;i1<=i;i1++){
			a[i1]*=i;
		}
		for(int i1=0;i1<=100;i1++){
			a[i1+1]+=a[i1]/10;
			a[i1]%=10;
		}
		for(int i1=0;i1<100;i1++){
			s[i1]+=a[i1];
			s[i1+1]+=s[i1]/10;
			s[i1]%=10;
		}
	}
	int b=0;
	for(int i=99;i>=0;i--){
		if(s[i]==0&&b==0){
			continue;
		}
		b++;
		printf("%d",s[i]);
	}

    return 0;
}