#include <fstream>

using namespace std;
ifstream in("fact.in");
ofstream out("fact.out");

int r(int t){
    int o=0;
while(t%25==0)
    {
        o++;
        t=t/25;
    }
    return o;
}



int main()
{
    long long n,p,k=0,j,a,i,s=0;
    in>>n;
    a=n;
    a++;
if (n==0)out<<1;
else {
    for(i=1; i<=n; i++)
    {
        s=s+5;
        if(s%25==0){n-=r(s);}
    }

    for(i=1; i<=a; i++)
    {
        k=k+5;
        if(k%25==0){a-=r(k);}
    }
    if(k==s){out<<-1;}
    else {out<<s;}
}
    return 0;
}