#include <fstream>

using namespace std;

int main (void)
{
    ifstream f_in("fact.in");
    ofstream f_out("fact.out");
    
    unsigned long P;
    f_in>>P;
    f_in.close();
    
    if (P == 0) f_out<<"1\n";
    else if (P == 1) f_out<<"5\n";
    else if (P == 2) f_out<<"10\n";
    else {
	    unsigned int nr_zerouri=0,se_imparte=0;
	    bool gasit=false;
	    for (unsigned int i=1; !gasit; i++) {
	        if (i%5==0) {
	            se_imparte++; nr_zerouri += se_imparte;
	        }
	        nr_zerouri++;
	        if (nr_zerouri == P) {
	            gasit = true;
	            f_out << ((unsigned long long)i)*5 << '\n';
	        } else if (nr_zerouri > P) {
	            gasit = true;
	            f_out << "-1\n";
	        }
	    }
    }
    
    f_out.close();
    return 0;
}