#include <fstream>
//#include <iostream>
#include <vector>
#include <algorithm>
#include <queue>
#include <map>
#include <set>
#include <unordered_map>
#include <time.h>
#include <iomanip>
#include <deque>
#include <math.h>
#include <cmath>
#include <assert.h>
#include <stack>
#include <bitset>
#include <random>
#include <chrono>
#include <string>
using namespace std;
ifstream cin("fact.in");
ofstream cout("fact.out");

long long zero(long long x)
{
    long long S=0;
    while(x/5LL){
        S=S+(x/5LL);
        x=x/5LL;
    }
    return S;
}
int main()
{
    int p;
    cin>>p;
    long long now=1;
    for(int i=0;i<=1e5;i++){
        long long A=zero(now);
        long long B=zero(now+1e5);
        if(A<=p&&B>=p){
        for(int j=now;j<=now+1e5;j++){
            if(zero(j)==p){
                cout<<j;
                return 0;
            }
        }
    }
    now=now+1e5;
} cout<<-1;
return 0;}