#include // {{{ // https://codeforces.com/blog/entry/96344 #pragma GCC optimize("O2,unroll-loops") #pragma GCC target("avx2,bmi,bmi2,lzcnt,popcnt") using namespace std; template constexpr T MIN = std::numeric_limits::min(); template constexpr T MAX = std::numeric_limits::max(); template [[nodiscard]] static T sc(auto &&x) { return static_cast(x); } template [[nodiscard]] static T sz(auto &&x) { return static_cast(x.size()); } using ll = long long; using ld = long double; template using vec = std::vector; template using arr = std::array; #define ff first #define ss second #define eb emplace_back #define pb push_back #define all(x) (x).begin(), (x).end() #define rall(x) (x).rbegin(), (x).rend() // }}} #include #include using namespace __gnu_pbds; // https://mirror.codeforces.com/blog/entry/124683 namespace hashing { using i64 = std::int64_t; using u64 = std::uint64_t; static const u64 FIXED_RANDOM = std::chrono::steady_clock::now().time_since_epoch().count(); #if USE_AES std::mt19937 rd(FIXED_RANDOM); const __m128i KEY1{(i64)rd(), (i64)rd()}; const __m128i KEY2{(i64)rd(), (i64)rd()}; #endif template struct custom_hash {}; template inline void hash_combine(u64 &seed, T const &v) { custom_hash hasher; seed ^= hasher(v) + 0x9e3779b97f4a7c15 + (seed << 12) + (seed >> 4); }; template struct custom_hash::value>::type> { u64 operator()(T _x) const { u64 x = _x; #if USE_AES __m128i m{i64(u64(x) * 0xbf58476d1ce4e5b9u64), (i64)FIXED_RANDOM}; __m128i y = _mm_aesenc_si128(m, KEY1); __m128i z = _mm_aesenc_si128(y, KEY2); return z[0]; #else x += 0x9e3779b97f4a7c15 + FIXED_RANDOM; x = (x ^ (x >> 30)) * 0xbf58476d1ce4e5b9; x = (x ^ (x >> 27)) * 0x94d049bb133111eb; return x ^ (x >> 31); #endif } }; template struct custom_hash()))>> { u64 operator()(T const &a) const { u64 value = FIXED_RANDOM; for (auto &x : a) hash_combine(value, x); return value; } }; template struct custom_hash> { u64 operator()(const std::tuple &a) const { u64 value = FIXED_RANDOM; std::apply( [&value](T const &...args) { (hash_combine(value, args), ...); }, a); return value; } }; template struct custom_hash> { u64 operator()(std::pair const &a) const { u64 value = FIXED_RANDOM; hash_combine(value, a.first); hash_combine(value, a.second); return value; } }; }; // namespace hashing #ifdef PB_DS_ASSOC_CNTNR_HPP template using hashtable = gp_hash_table< Key, Value, hashing::custom_hash, std::equal_to, direct_mask_range_hashing<>, linear_probe_fn<>, hash_standard_resize_policy, hash_load_check_resize_trigger<>, true>>; #endif #ifdef PB_DS_TREE_POLICY_HPP template using multiset = tree, rb_tree_tag, tree_order_statistics_node_update>; template using rbtree = tree, rb_tree_tag, tree_order_statistics_node_update>; #endif void solve() { int n; cin >> n; ll x; ll ans = 0; set seen; while (n--) { cin >> x; if (seen.find(x) == seen.end()) ++ans; seen.insert(x); } cout << ans << endl; } int main() { // {{{ cin.tie(nullptr)->sync_with_stdio(false); solve(); return 0; } // }}}