#include <fstream>

using namespace std;

int trailingZeros(int n){
    int cnt = 0;
    while(n!=0){
        n = n/5;
        cnt += n;
    }
    return cnt;
}

int main(){
    int p;

    ifstream fin("fact.in");
    fin>>p;
    fin.close();

    ofstream fout("fact.out");
    for(int i = 0; i<4000000000; i+=5){
        if(trailingZeros(i)==p) {fout<<i; break;}
        if(trailingZeros(i)>p) {fout<<-1; break;}
    }
    fout.close();

    return 0;
}