#include <bits/stdc++.h>

using namespace std;

#ifdef LOCAL
#include "../debug.h"
#define debug(...) cerr << "[" << #__VA_ARGS__ << "]:", debug_out(__VA_ARGS__)
#else
#define debug(...) 42
#endif
#define fst first
#define snd second
#define fore(i,a,b) for(int i=a,ThxDem=b;i<ThxDem;++i)
#define pb push_back
using ll = long long;

ll gcd(ll a, ll b){return a?gcd(b%a,a):b;}
ll mulmod(ll a, ll b, ll m) {
	ll r=a*b-(ll)((long double)a*b/m+.5)*m;
	return r<0?r+m:r;
}
ll expmod(ll b, ll e, ll m){
	if(!e)return 1;
	ll q=expmod(b,e/2,m);q=mulmod(q,q,m);
	return e&1?mulmod(b,q,m):q;
}
bool is_prime_prob(ll n, int a){
	if(n==a)return true;
	ll s=0,d=n-1;
	while(d%2==0)s++,d/=2;
	ll x=expmod(a,d,n);
	if((x==1)||(x+1==n))return true;
	fore(_,0,s-1){
		x=mulmod(x,x,n);
		if(x==1)return false;
		if(x+1==n)return true;
	}
	return false;
}
bool rabin(ll n){ // true iff n is prime
	if(n==1)return false;
	int ar[]={2,3,5,7,11,13,17,19,23};
	fore(i,0,9)if(!is_prime_prob(n,ar[i]))return false;
	return true;
}
// optimized version: replace rho and fact with the following:
const int MAXP=1e6+100; // sieve size
int sv[MAXP]; // sieve
ll add(ll a, ll b, ll m){return (a+=b)<m?a:a-m;}
ll rho(ll n){
	static ll s[MAXP];
	while(1){
		ll x=rand()%n,y=x,c=rand()%n;
		ll *px=s,*py=s,v=0,p=1;
		while(1){
			*py++=y=add(mulmod(y,y,n),c,n);
			*py++=y=add(mulmod(y,y,n),c,n);
			if((x=*px++)==y)break;
			ll t=p;
			p=mulmod(p,abs(y-x),n);
			if(!p)return gcd(t,n);
			if(++v==26){
				if((p=gcd(p,n))>1&&p<n)return p;
				v=0;
			}
		}
		if(v&&(p=gcd(p,n))>1&&p<n)return p;
	}
}
void init_sv(){
	fore(i,2,MAXP)if(!sv[i])for(ll j=i;j<MAXP;j+=i)sv[j]=i;
}
void fact(ll n, map<ll,int>& f){ // call init_sv first!!!
	for(auto&& p:f){
		while(n%p.fst==0){
			p.snd++;
			n/=p.fst;
		}
	}
	if(n<MAXP)while(n>1)f[sv[n]]++,n/=sv[n];
	else if(rabin(n))f[n]++;
	else {ll q=rho(n);fact(q,f);fact(n/q,f);}
}
const ll oo = 1e18+1;
ll x;
ll ans = 1e18+1;
void solve(int i, vector<pair<ll,int>>& v, ll p, ll num){
	if(i == int(v.size())){
		if(p <= 62){
			bool ok = 1;
			ll y = x;
			while(p){
				if(y < 1) break;
				ok &= y%num==0;
				y/=num;
				p--;
			}
			if(ok && y == 1 && p == 0) ans = min(ans,num);
		}
	}else{
		ll cur = 1;
		for(ll j=0; j<=v[i].second; j++){
			solve(i+1,v,p*(j+1),cur*num);
			cur *= v[i].first;
		}
	}
}
int main(){
	ios_base::sync_with_stdio(0); cin.tie(0);
	cin>>x;
	init_sv();
	map<ll,int> f;
	fact(x,f);
	vector<pair<ll,int>> dv;
	for(auto& [p,e] : f){
		dv.push_back(make_pair(p,e));
	}
	solve(0,dv,1,1);
	cout<<(ans == oo ? -1 : ans)<<'\n';
	return 0;
}