#943 Suma4

#include <iostream>

using namespace std;

int main ()
{
    int N,s=0,x;
    cin >> N;
    N%=100;
    for (int i = 1; i<= N;++i)
    {
        x=i%10;
        s=(s+x*x*x*x)%10;

    }
    cout << s;

  return 0;
}