#include<iostream> //header file
 
using namespace std;
 
int main()
 
{
 
    long long n,fact=1; 
 
    cout<<" Enter Number:  ";
 
    cin>>n;
 
    for(int i=1;i<=n;i++)
 
    {
 
        fact=fact*i; 
 
    }
 
     cout<<fact;
 
     return 0;
 
}