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#include <cstdio>
#include <vector>
#include <algorithm>
#include <map>
#include <unordered_map>
using namespace std;

int nextInt() { int n; scanf("%d", &n); return n; }

unordered_map<int, int> m;

int solve(int n) {
	int res = 0;

	vector<int> v;
	v.reserve(m.size());
	for (auto it = m.begin(); it != m.end(); ++it)
		v.push_back(it->second);
	sort(v.begin(), v.end());

	int a = 0;
	int b = v.size() - 1;
	while (a < b) {
		++res;
		int cnt = v[b];
		if (cnt + cnt > n) return res;
		if (1 == cnt) return res + b - a;
		n -= cnt + cnt - 1;
		--b;
		--cnt;
		while (v[a] <= cnt) {
			cnt -= v[a];
			++a;
		}
		if (cnt > 0) v[a] -= cnt;
	}
	if (a == b) ++res;

	return res;
}

int main() {
	int n = nextInt();
	for (int i = 0; i < n; ++i)
		++m[nextInt()];

	int res = solve(n);
	printf("%d\n", res);
	return 0;
}