#include <iostream>
#include <fstream>
using namespace std;
ifstream in("fact.in");
ofstream out("fact.out");
int main()
{  int p,i,j,k,j1;
in>>p;
if(p==0)
        out<<1;
else
    {i=0;k=0;
        for(j=5;j<=999999999
        ;j=j+5)
            {j1=j;
            while(j1%5==0)
                {k++;
                j1=j1/5;
                }
            if(k==p)
                break;
        }
    out<<j;
    }
return 0;
}