#include<iostream>
#include<cstdio>
using namespace std;

int n,a[35700]={1},c=0;

int main(){
	cin>>n;
   if(n==0)cout<<1;
   else{
	for(int j=1;j<=n;j++){
		for(int i=0;i<=35700;i++){
			a[i]=a[i]*j+c;
			if(a[i]>9){
				c=a[i]/10;
				a[i]=a[i]%10;
			}
			else c=0;
		}
	}
	int j=35700;
	while(a[j]==0){
		j--;
	}
	for(;j>=0;j--)
		cout<<a[j];
  	}
	return 0;
}