#include<iostream>
#include<stdio.h>
#define Nmax 100000000
using namespace std;

int main()
{
    int i, d, N, x, P, nr2, nr5;
    nr2 = nr5 = 0;

    freopen("fact.in","r", stdin);
    freopen("fact.out", "w", stdout);

    cin >> P;
    x = 1;

    while(x <= Nmax)
    {
        N = x;
        while(N % 2 == 0)
        {
            N /= 2;
            nr2++;
        }
        while(N % 5 == 0)
        {
            N /= 5;
            nr5++;
        }

        if(min(nr2, nr5) == P)
        {
            cout << x;
            return 0;
        }
        x++;
    }
    cout << '1';
    return 0;
}