// Hallelujah, praise the one who set me free
// Hallelujah, death has lost its grip on me
// You have broken every chain, There's salvation in your name
// Jesus Christ, my living hope
#include <bits/stdc++.h> 
using namespace std;

#define REP(i, s, e) for (int i = (s); i < (e); i++)
#define RREP(i, s, e) for (int i = (s); i >= (e); i--)
template <class T>
inline bool mnto(T& a, T b) {return a > b ? a = b, 1 : 0;}
template <class T>
inline bool mxto(T& a, T b) {return a < b ? a = b, 1: 0;}
typedef long long ll;
typedef long double ld;
#define FI first
#define SE second
typedef pair<int, int> ii;
typedef pair<ll, ll> pll;
typedef tuple<int, int, int> iii;
#define ALL(_a) _a.begin(), _a.end()
#define SZ(_a) (int) _a.size()
#define pb push_back
typedef vector<int> vi;
typedef vector<ll> vll;
typedef vector<ii> vii;
typedef vector<iii> viii;

#ifndef DEBUG
#define cerr if (0) cerr
#endif

const int INF = 1000000005;
const ll LINF = 1000000000000000005ll;
const int MAXN = 1000005;

ll x;
vi vc;

ll rt(ll x, ll p) {
    ll lo = 1, hi = x;
    while (lo < hi) {
        ll mid = lo + hi + 1 >> 1;
        ll res = 1;
        bool pos = 1;
        REP (z, 0, p) {
            if (res > x / mid) {
                pos = 0;
                break;
            }
            res = res * mid;
        }
        if (pos) {
            lo = mid;
        } else {
            hi = mid - 1;
        }
    }
    cerr << x << ' ' << p << ": " << lo << '\n';
    return lo;
}

int main() {
#ifndef DEBUG
    ios::sync_with_stdio(0), cin.tie(0);
#endif
    cin >> x;
    if (x == 1) {
        cout << 1 << '\n';
        return 0;
    }
    ll ox = x;
    REP (i, 2, MAXN) {
        int cnt = 0;
        while (x % i == 0) {
            x /= i;
            cnt++;
        }
        if (cnt) {
            vc.pb(cnt);
        }
    }
    if (x > 1) {
        ll sq = rt(x, 2);
        if (sq * sq == x) {
            vc.pb(2);
        } else {
            vc.pb(1);
        }
    }
    int g = 0;
    for (int c : vc) {
        g = __gcd(g, c);
    }
    int fnd = -1;
    REP (i, 1, g + 1) {
        ll prod = 1;
        if (g % i) {
            continue;
        }
        for (int c : vc) {
            prod *= c / g * i + 1;
        }
        if (prod == g / i) {
            fnd = i;
            break;
        }
    }
    if (fnd == -1) {
        cout << -1 << '\n';
    } else {
        cout << rt(ox, g / fnd) << '\n';
    }
    return 0;
}