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#include <algorithm>
#include <cstdio>
#include <cstring>
#include <vector>

int solve(int n, const int* counter) {
  std::vector<int> data;
  for (int i = 1; i <= n; ++i) {
    if (0 < counter[i]) {
      data.emplace_back(counter[i]);
    }
  }
  std::sort(data.rbegin(), data.rend());

  int solutions = 0;
  for (const auto& count : data) {
    solutions++;
    n -= count + count - 1;
    if (n <= 0) {
      break;
    }
  }
  return solutions;
}

int main() {
  constexpr auto MAX_N = 500000;
  int n, value, counter[MAX_N + 1];
  std::fill_n(counter, MAX_N + 1, 0);
  scanf("%d\n", &n);
  for (int i = 0; i < n; ++i) {
    scanf("%d", &value);
    counter[value]++;
  }
  printf("%d\n", solve(n, counter));
}