#include <bits/stdc++.h>
#include "grader.h"
using namespace std;
void solve(int n)
{
vector<int> r;
for (int i = 1; i <= n; i++) r.push_back(i);
random_shuffle(r.begin(), r.end());
map<int, int> m;
set<int> s;
for (int i = 0; i < min(n, 49); i++) {
int val = kth(r[i]);
m[val]++;
s.insert(val);
}
vector<pair<int, int> > totals;
for (int i: s) {
totals.emplace_back(-m[i], i);
}
sort(totals.begin(), totals.end());
for (int i = 0; i < min((int)totals.size(), 10); i++) {
if (cnt(totals[i].second) > n/3) {
say_answer(totals[i].second);
return;
}
}
say_answer(-1);
return;
}
