#include <bits/stdc++.h>
using namespace std;
#if __has_include(<atcoder/all>)
#include <atcoder/all>
using namespace atcoder;
#endif
using ll = long long;
using ld = long double;
#define all(s) (s).begin(),(s).end()
#define rep2(i, m, n) for (int i = (m); i < (n); ++i)
#define rep(i, n) rep2(i, 0, n)
#define drep2(i, m, n) for (int i = (m)-1; i >= (n); --i)
#define drep(i, n) drep2(i, n, 0)
#define rever(vec) reverse(vec.begin(), vec.end())
#define sor(vec) sort(vec.begin(), vec.end())
#define fi first
#define se second
#define P pair<ll,ll>
const ll mod = 998244353;
//const ll mod = 1000000007;
const ll inf = 2000000000000000000ll;
static const long double pi = 3.141592653589793;
void vcin(vector<ll> &n){for(int i=0;i<int(n.size());i++) cin>>n[i];}
void vcout(vector<ll> &n){for(int i=0;i<int(n.size());i++){cout<<n[i]<<" ";}cout<<endl;}
void YesNo(bool a){if(a){cout<<"Yes"<<endl;}else{cout<<"No"<<endl;}}
void YESNO(bool a){if(a){cout<<"YES"<<endl;}else{cout<<"NO"<<endl;}}
template<class T,class U> void chmax(T& t,const U& u){if(t<u) t=u;}
template<class T,class U> void chmin(T& t,const U& u){if(t>u) t=u;}
ll modPow(ll a, ll n, ll mod) { ll ret = 1; ll p = a % mod; while (n) { if (n & 1) ret = ret * p % mod; p = p * p % mod; n >>= 1; } return ret; }
bool check(ll a,ll p){
  ll tmp=a%p;
  while(a){
    if(a%p!=tmp){
      return false;
    }
    a/=p;
  }
  return true;
}
int main() {
  /* mod は 1e9+7 */
  ios::sync_with_stdio(false);
    std::cin.tie(nullptr);
  cout<< fixed << setprecision(10);
  ll a;
  cin>>a;
  ll ans=a-1;
  for(ll i=1;i*i<=a;i++){
    if(a%i==0){
      ll x=i;
      for(ll j=1;j*j<=a/i-1;j++){
        if((a/i-1)%j==0){
          if(j>=2&&check(a,j)){
            chmin(ans,j);
          }
          if((a/i-1)/j>=2&&check(a,(a/i-1)/j)){
            chmin(ans,(a/i-1)/j);
          }
        }
      }
      for(ll j=1;j*j<=a/(a/i)-1;j++){
        if((a/(a/i)-1)%j==0){
          if(j>=2&&check(a,j)){
            chmin(ans,j);
          }
          if((a/(a/i)-1)/j>=2&&check(a,(a/(a/i)-1)/j)){
            chmin(ans,(a/(a/i)-1)/j);
          }
        }
      }
    }
  }
  cout<<ans<<endl;
}