#include<bits/stdc++.h>
using namespace std;
int main()
{
    int a;
    cin>>a;
    int i=1;long long b=1;
    while(i<a)
    {b=b*(i+1);i++;}
     i=10;
   while(b%i==0)
    {
        b=b/10;
    }
    cout<<b%i<<endl;
    return 0;
}