/// Frail the skin is dry and pale
#pragma GCC optimize("O3")
#pragma GCC optimize ("unroll-loops")
#pragma GCC target("avx,avx2,fma")
using namespace std;

#include "bits/stdc++.h"
#include <ext/pb_ds/tree_policy.hpp>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/rope>

using namespace __gnu_pbds;
using namespace __gnu_cxx;

using ll = long long;
using ii = pair<int, int>;

template<typename T>
using ordered_set = tree<T, null_type, less<T>, rb_tree_tag, tree_order_statistics_node_update>;

#define pb push_back
#define F first
#define S second
#define f(i, a, b)  for(int i = a; i < b; i++)
#define all(a)  a.begin(),a.end()
#define rall(a) a.rbegin(),a.rend()
#define sz(x) (int)(x).size()
#define mp make_pair

const int N = 5e4 + 5, LG = 18, MOD = 31607;
const double PI = acos(-1);
void doWork() {

    int n;
    cin >> n;
    n--;
    vector<int> a(n);
    f(i,0,n)    cin >> a[i];

    bool f = false;
    int ans = 0;
    for(int i = 0; i < n; i++) {
        if(a[i] != 0) {
            vector<int> v;
            for(int j = i; j < n && a[j] > 0; ++j) {
                if(v.empty() || v.back() != (a[j] & 1))
                    v.pb(a[j] & 1);
                a[j] = 0;
            }
            if(v.size() == 1) {
                ans += 1;
                continue;
            }
            ans += accumulate(all(v), 0);
        }
    }
    cout << ans - 1 << '\n';
}
int32_t main() {
#ifdef ONLINE_JUDGE
    ios_base::sync_with_stdio(0);
    cin.tie(0);
#endif // ONLINE_JUDGE
    int t = 1;
//    cin >> t;
    while (t--) {
        doWork();
    }


    return 0;
}