#include <iostream>
#include <vector>
#include <string>
#include <algorithm>
using namespace std;
const int maxn = 2002;
const int INF = 1e9;
vector<pair<int, int> > graph[maxn];
int n;
int dp[maxn][4100];
int rek(int at, int number) {
    if(at >= n) {
        return 0;
    }
    if(dp[at][number] != -1) {
        return dp[at][number];
    }
    int res = INF;
    for(int i = 0; i < (int) graph[at].size(); i++) {
        int nxt_number = graph[at][i].first;
        int swaps = graph[at][i].second;

        if(number <= nxt_number) {
            res = min(res, rek(at + 1, nxt_number) + swaps);
        }
    }
    return dp[at][number] = res;
}
int main()
{

    cin >> n;
    vector<int> v(n);

    for(int i = 0; i < n; i++) {
        cin >> v[i];
    }
    for(int i = 0; i < n; i++) {
        for(int j = 0; j <= 4095; j++) {
            dp[i][j] = -1;
            if(__builtin_popcount(j) == __builtin_popcount(v[i])) {
                int swaps = __builtin_popcount(v[i] ^ j) / 2;
                graph[i].push_back(make_pair(j, swaps));
            }
        }
    }

    cout << rek(0, 0) << endl;
    return 0;
}