#include <fstream>
using namespace std;
ifstream f("fact.in");
ofstream g("fact.out");
int P;
void Solve()
{
    int i=5,Sol=0;
    while(Sol<P)
    {
        int aux=i;
        while(aux%5==0)
            aux/=5,Sol++;
        i+=5;
    }
    if(P==0)
        g<<1<<"\n";
    else
        g<<i-5<<"\n";
}
int main()
{
    f>>P;
    Solve();
    return 0;
}