#include <iostream>
#include <fstream>
#define MOD 10

using namespace std;

ifstream fin("kfib.in");
ofstream fout("kfib.out");

int k;
int fib[100];

int main()
{
    int x, y, s = 0;
    fin >> k;
    x = 0;
    y = 1;

    int rep;//indicele de repetare

    for(int i = 2; i <= k; i++)
    {
      cout<<"i = "<<i<<"\n";
        fib[i] = (fib[i-1] + fib[i-2])% MOD;
        /*if(fib[i-1]==0 && fib[i]==1)
        {
          cout<<"Ne repetam!\n";
          rep = i-1;
          cout<<"rep = "<<rep<<"\n";
          break;
        }*/

    }
    cout<<"rep este "<<rep<<"\n";
    k = k%rep;
    fout << fib[k] << "\n";

    fout.close();
    return 0;
}