#include #define REP(i,n) for (int i = 0; i < (n); ++i) template inline bool chmin(T& a, T b) {if (a > b) {a = b;return true;}return false;} template inline bool chmax(T& a, T b) {if (a < b) {a = b;return true;}return false;} using namespace std; using ll = long long; using P = pair; using Pl = pair; using veci = vector; using vecl = vector; using vecveci = vector>; using vecvecl = vector>; const int MOD = 1000003; const double pi = acos(-1); ll gcd(ll a, ll b) {if(b == 0) return a; else return gcd(b,a%b);} ll lcm(ll a, ll b) {return a*b/gcd(a,b);} template struct Fp { long long val; constexpr Fp(long long v = 0) noexcept : val(v % MOD) {if (val < 0) val += MOD;} constexpr int getmod() { return MOD; } constexpr Fp operator - () const noexcept {return val ? MOD - val : 0;} constexpr Fp operator + (const Fp& r) const noexcept { return Fp(*this) += r; } constexpr Fp operator - (const Fp& r) const noexcept { return Fp(*this) -= r; } constexpr Fp operator * (const Fp& r) const noexcept { return Fp(*this) *= r; } constexpr Fp operator / (const Fp& r) const noexcept { return Fp(*this) /= r; } constexpr Fp& operator += (const Fp& r) noexcept {val += r.val;if (val >= MOD) val -= MOD;return *this;} constexpr Fp& operator -= (const Fp& r) noexcept {val -= r.val;if (val < 0) val += MOD;return *this;} constexpr Fp& operator *= (const Fp& r) noexcept {val = val * r.val % MOD;return *this;} constexpr Fp& operator /= (const Fp& r) noexcept {long long a = r.val, b = MOD, u = 1, v = 0;while (b) {long long t = a / b;a -= t * b; swap(a, b);u -= t * v; swap(u, v);}val = val * u % MOD;if (val < 0) val += MOD;return *this;} constexpr bool operator == (const Fp& r) const noexcept {return this->val == r.val;} constexpr bool operator != (const Fp& r) const noexcept {return this->val != r.val;} friend constexpr ostream& operator << (ostream &os, const Fp& x) noexcept {return os << x.val;} friend constexpr Fp modpow(const Fp &a, long long n) noexcept {if (n == 0) return 1;auto t = modpow(a, n / 2);t = t * t;if (n & 1) t = t * a;return t;} }; using mint = Fp; int main() { ll N; cin >> N; vecl p; for(ll i = 1; i*i <= N; i++) { if(N%i == 0) { p.push_back(i); if(N/i != i) p.push_back(N/i); } } sort(p.begin(),p.end()); ll ans = 0; for(auto x : p) { if(((N-1)*N/2)%x == 0) ans = x; } cout << ans << endl; }