#include <fstream>
using namespace std;
ifstream fin("factorial.in");
ofstream fout("factorial.out");
int main() {
    long long p, i=5, c=0, nr=0;
    fin>>p; fin.close();
    if(p==0) {
        fout<<1;
    }
    else {
        do {
            nr=i;
            while(nr%5==0) {
                nr/=5;
                c++;
            }
            i+=5;
        }while(c<p);
        fout<<i-5<<endl;
    }
    fout.close();
    return 0;
}