#include <iostream>
#include <algorithm>
#include <iomanip>
#include <vector>
#include <queue>
#include <set>
#include <map>
#include <cassert>

#define debug_value(x) cerr << "line" << __LINE__ << ":<" << __func__ << ">:" << #x << "=" << x << endl;
#define debug(x) cerr << "line" << __LINE__ << ":<" << __func__ << ">:" << x << endl;

template<class T> inline bool chmax(T& a, T b) { if (a < b) { a = b; return 1; } return 0; }
template<class T> inline bool chmin(T& a, T b) { if (a > b) { a = b; return 1; } return 0; }

using namespace std;
typedef long long ll;

bool ok(ll n, ll m){
    ll tmp = m;
    set<ll> st;
    while(n){
        st.insert(n%m);
        n /= m;
    }
    return st.size() == 1;
}

int main(){
    ios::sync_with_stdio(false);
    cin.tie(0);
    cout << setprecision(10) << fixed;
    ll n; cin >> n;
    if(n == 1){
        cout << 2 << endl;
        return 0;
    }
    if(n == 2){
        cout << 3 << endl;
        return 0;
    }
    ll ans = 1e15;
    for(ll m = 2; m*m <= n; m++){
        if(ok(n, m)) chmin(ans, m);
    }

    for(ll k = 1; k*k <= n; k++){
        if(n%k != 0) continue;
        ll m = (n/k)-1;
        if(k < m && m*m > n) chmin(ans, m);
    }
    cout << ans << endl;
}