#include <bits/stdc++.h>
using namespace std;
using ll = long long;
template<class T> using vec = vector<T>;
template<class T> using vvec = vector<vec<T>>;
template<class T> bool chmin(T& a,T b){if(a>b) {a = b; return true;} return false;}
template<class T> bool chmax(T& a,T b){if(a<b) {a = b; return true;} return false;}
#define all(x) (x).begin(),(x).end()
#define debug(x)  cerr << #x << " = " << (x) << endl;

int main(){
    cin.tie(0);
    ios::sync_with_stdio(false);
    ll N;
    cin >> N;
    if(N==1){
        cout << 2 << "\n";
    }
    ll ans = N+1;
    if(N>2) ans = N-1;
    for(ll i=2;i*i<=N;i++){
        ll a = i;
        while(true){
            a *= i;
            ll now = (a-1)/(i-1);
            if(now>N) break;
            if(N%now==0 && N/now<i) chmin(ans,i);
        }
    }
    cout << ans << "\n";
}