include <bits/stdc++.h>

using namespace std;

int main() {

int n, sum = 0, t, q;
cin >> n;
int a[10001] = {0}, x = n / 2;
int k;
for (t = 0; t < n; t++) {
	cin >> k;
	a[k]++;//桶排序
}
for (q = 0; q < 10001; q++) {

`#include <bits/stdc++.h> using namespace std;

int main() {

int n, sum = 0, t, q;
cin >> n;
int a[10001] = {0}, x = n / 2;
int k;
for (t = 0; t < n; t++) {
	cin >> k;
	a[k]++;//桶排序
}
for (q = 0; q < 10001; q++) {
	if (a[q] != 0) {
		sum++;
	}
}
if (sum > x) {
	cout << x;
	return 0;
} else {
	cout << sum;
}
return 0;

}`