#include<iostream>using namespace std;int main(){int i,n,m=1;int sum=1;cin>>n;for(i=1;i<=n;i++){sum=sum*i;}cout<<sum<<endl;return 0;}

#include <stdio.h> int main() { int n,f=1; scanf("%d",&n); for (int i=1;i<=n;i++){

f*=i;}
printf("%d",f);
return 0;

}