#include <iostream>
#include <algorithm>
#include <vector>

int main() {
    std::ios_base::sync_with_stdio(0);
    int n;
    std::cin >> n;
    std::vector<int> counts(n);
    for(int i = 0; i < n; ++i) {
        int num;
        std::cin >> num;
        counts[num - 1] += 1;
    }
    std::sort(counts.begin(), counts.end(), std::greater<int>());
    int l = 0, r = n - 1;
    int result = 0;
    while(l <= r && counts[l] > 0) {
        while(counts[r] == 0 && r > l) {
            --r;
        }

        if(counts[l] <= counts[r]) {
            if(l != r) {
                counts[r] -= counts[l] - 1;
            }
            counts[l] = 0;
        } else {
            counts[l] -= counts[r];
            counts[r] = 0;
            if(counts[l] == 1) {
                counts[l] = 0;
            }
        }

        if(counts[l] == 0) {
            ++result;
            ++l;
        } else {
            --r;
        }
    }
    std::cout << result << "\n";
}