#include <iostream>
#include <vector>
#include <string>
#include <cstdlib>
#include <numeric>
#include <algorithm>
#include <cstdio>
#include <cstring>
#include <stack>
#include <math.h>
#include <string.h>
#include <map>
#include <set>
#include <bitset>
#include <queue>

#define ln cout<<'\n'
#define ll long long
#define ld long double
#define rep(i, n) for(int i = 0; i < (n); ++i)
// using P = pair<int,int>;
//ASCII a=97, A=65
// int H[N]; rep(i,N) scanf("%d", &H[i]);
// int max_x = *std::max_element(x.begin(), x.end());
// int min_y = *std::min_element(y.begin(), y.end());
// sort(vec.begin(), vec.end()); std::greater<>()
// reverse(vec.begin(), vec.end());
// scanf("%s",s);
// printf("%d\n",end-start+1);
// ceil (a + (b - 1)) / b

using namespace std;
using Edge = pair<int, ll>;
using Graph = vector<vector<Edge>>;
using pll = pair<long long, long long>;

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;}

int GCD(int a, int b) { return b ? GCD(b, a%b) : a; }
const long long INF = 1LL << 60;
const int MOD = 1000000007;

// struct UnionFind {
//     vector<int> par;
//     UnionFind(int n) : par(n, -1) { }
//     void init(int n) { par.assign(n, -1); }
    
//     int rt(int x) {
//         if (par[x] < 0) return x;
//         else return par[x] = rt(par[x]);
//     }
    
//     bool issame(int x, int y) {
//         return rt(x) == rt(y);
//     }
    
//     bool unite(int x, int y) {
//         x = rt(x);
//         y = rt(y);
//         if (x == y)  return false;
        
//         if (par[x] > par[y]) swap(x, y);
//         par[x] += par[y];
//         par[y] = x;
//         return true;
//     }
    
//     int size(int x) {
//         return -par[rt(x)];
//     }
// };

template<int MOD> struct Fp {
    long long val;
    constexpr Fp(long long v = 0) noexcept : val(v % MOD) {
        if (val < 0) v += 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<MOD>& x) noexcept {
        return os << x.val;
    }
    friend constexpr istream& operator >> (istream &is, Fp<MOD>& x) noexcept {
        return is >> x.val;
    }
    friend constexpr Fp<MOD> modpow(const Fp<MOD> &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<MOD>;



int main() {
    int N; cin >> N;
    set<int> se;
    rep (i, N) {
        int s; cin >> s;
        se.insert(s);
    }
    cout << se.size() << endl;
}
 















Measured memory_bytes: 256