#include "testlib.h"
#include <bits/stdc++.h>
using namespace std;
using ll = long long;
using pll = pair<ll, ll>;
#define all(a) begin(a), end(a)
#define space inf.readSpace()
#define endl inf.readEoln()
#define eof inf.readEof()
constexpr ll ten(int x){ return x ? ten(x - 1) * 10 : 1; }
tuple<ll> read(ll min, ll max){
    ll a = inf.readLong(min, max);
    endl;
    return tuple{a};
}
template<class... T> auto read(ll min, ll max, T... t){
    ll a = inf.readLong(min, max);
    space;
    return tuple_cat(tuple{a}, read(t...));
}
vector<ll> reads(ll N, ll min, ll max){
    auto a = inf.readLongs(N, min, max);
    endl;
    return a;
}
template<class... T> auto read_lines(ll N, T... t){
    vector<decltype(read(t...))> a;
    a.reserve(N);
    while(N--) a.push_back(read(t...));
    return a;
}

const ll N_MAX = 20, MAX = 1e3;
int main(){
    registerValidation();
    auto [N] = read(1, N_MAX);
    auto P = read_lines(N, 0, MAX, 0, MAX);
    ensure(set(all(P)).size() == N);
    eof;
}