#include <bits/stdc++.h>
using namespace std;
long long factorial(long long n) {
  return (n == 1 || n == 0) ? 1 : n * factorial(n - 1);
}
long long gcd(long long a, long long b) {
  if (a == 0) return b;
  return gcd(b % a, a);
}
long long lcm(long long a, long long b) { return (a * b) / gcd(a, b); }
bool sortByVal(const pair<long long, long long> &a,
               const pair<long long, long long> &b) {
  if (a.first == b.first)
    return a.second < b.second;
  else
    return a.first > b.first;
}
long long Powb(long long b, long long n) {
  if (n == 0) return 1LL;
  if (n == 1) return b;
  long long temp = Powb(b, n / 2);
  if (n % 2 == 0) {
    return (temp * temp) % 1000000007LL;
  } else {
    return (b * ((temp * temp) % 1000000007LL)) % 1000000007LL;
  }
}
int main() {
  ios::sync_with_stdio(false);
  cin.tie(0);
  cout.tie(0);
  ;
  int t = 1;
  while (t--) {
    long long i, j, m, n, k, sum = 0, c = 0, d = 0, e = 0, f = 0, g = 0, h = 0,
                             maxi = 0;
    cin >> n;
    vector<long long> a(n);
    for (int i = 0; i < n; i++) {
      cin >> a[i];
    };
    vector<long long> b, p;
    for (i = 0; i < n; i++) {
      if (a[i] % 2)
        b.push_back(a[i]);
      else
        p.push_back(a[i]);
    }
    n = b.size();
    m = p.size();
    sum += min(n, m);
    n -= min(n, m);
    m -= min(n, m);
    while (n >= 3) {
      sum++;
      n -= 3;
    }
    cout << sum << "\n";
  }
}
