#include <bits/stdc++.h>
#include "testlib.h"
using namespace std;
int main() {
    registerValidation();

    int n = inf.readInt(1, 100000, "n");
    inf.readEoln();
    set<int> s;
    for (int i = 0; i < n * n; ++i) {
        int a = inf.readInt(1, 1000000000, "a_i");
        inf.readEoln();
        assert(s.find(a) == s.end());
        s.emplace(a);
    }
    inf.readEof();

    return 0;
}