#include<iostream>
#include<fstream>
using namespace std;
  int p,n,nrz=0;
   ifstream f("fact.in");
   ofstream g("fact.out");
int main()
{
    f>>p;
     long long i;
     if(p==0) g<<1;
       else
           for (i=5;i<=1000000000;i+=5)
            {
                if (i%5==0) nrz++;
                 if (i==25) nrz++;
                 if (nrz==p) {g<<i;i=1000000001;}
            }

}