#include <fstream>

using namespace std;

ifstream in("fact.in");
ofstream out("fact.out");

int main ()
{
    long long n, i, nr=0, k, x;
    in>>n;
    if(n==0) {out<<1; return 0;}



        for (i=5; i<=100000000000000; i=i+5)
        {
            k=i;
            while (k%5==0)
            {
                k=k/5;
                n--;
            }
            if (n<=0) {out<<i; return 0;}
        }

}