#ifdef EZ
   #include "./ez/ez.h"
#else
   #include <bits/stdc++.h>
#endif
#define mp make_pair
#define mt make_tuple
#define ll long long
#define pb push_back
#define fi first
#define se second
using namespace std;
const string FILE_NAME = "fact";
ifstream fin (FILE_NAME + ".in");
ofstream fout (FILE_NAME + ".out");

int main()
{
   int p;
   fin >> p;

   int zeros = 0, i;
   for (i = 5; zeros < p; i += 5)
      for (int x = i; x % 5 == 0; x /= 5)
         zeros ++;
   
   if (zeros == p)
      fout << max(i-5, 1);
   else
      fout << "-1";
}