#include <vector>
#include <iostream>
#include <cmath>
#include <map>
#include <unordered_map>
#include <algorithm>
#include <fstream>
#include <unistd.h>
#include <string.h>
#include <string>
#include <numeric>
#include <queue>
#include <deque>
#include <sstream>
#include <iomanip>
#include <set>
#include <stack>
#include <cassert>
using namespace std;
typedef long long ll;
typedef vector<int> vi;
typedef vector<ll> vl;
typedef vector<vl> vvl;
typedef vector<vvl> vvvl;
typedef vector<vi> vvi;
typedef vector<vvi> vvvi;
typedef vector<bool> vb;
typedef vector<vector<bool>> vvb;
typedef vector<vvb> vvvb;
typedef vector<vvvb> vvvvb;
typedef vector<string> vs;
typedef vector<vs> vvs;
typedef vector<vvs> vvvs;
typedef vector<char> vc;
typedef vector<vector<char>> vvc;
typedef vector<double> vd;
typedef vector<vd> vvd;
typedef vector<vvd> vvvd;
typedef pair<ll, ll> PL;
typedef vector<PL> vpl;
typedef vector<vector<PL>> vvpl;
const int INF = 1001001001;
const ll LINF = 1e17;
const double pi = 3.1415926535897932;
const string endstr = "\n";
#define FOR(i, a, b) for(ll i = (a); i < b; i++)
#define RFOR(i, a, b) for(ll i = (a); i > b; i--)
#define rep(i, n) for(ll i = 0; i < n; i++)
#define rrep(i, n) for(ll i = n-1; i > -1; i--)
#define FORMAP(it, m) for(auto it = m.begin(); it != m.end(); it++)
#define ff first
#define ss second
#define pb push_back
#define epb emplace_back
#define ALL(X) (X).begin(),(X).end()

template <typename T>
T gcd(T a, T b) {
    return (a == 0) ? b : gcd(b%a, a);
}
template <typename T>
T lcm(T a, T b) {
    return a / gcd(a, b) * b;
}

bool p_comp_fs(const PL p1, const PL p2){ return p1.first < p2.first;};
bool p_comp_fg(const PL p1, const PL p2){ return p1.first > p2.first;};
bool p_comp_ss(const PL p1, const PL p2){ return p1.second < p2.second;};
bool p_comp_sg(const PL p1, const PL p2){ return p1.second > p2.second;};
template <typename T>
vector<T> uniquen(vector<T> vec){
    vec.erase(unique(vec.begin(), vec.end()), vec.end());
    return vec;
}

inline ll popcnt(ll x){return __builtin_popcountll((unsigned long long)x);};
template<class T> bool chmax(T &a, T b) { if (a < b) { a = b; return true; } return false; }
template<class T> bool chmin(T &a, T b) { if (a > b) { a = b; return true; } return false; }




int main(){
    ios_base::sync_with_stdio(false);
    cin.tie(nullptr);
    ll L; cin >> L;
    vl A(L); rep(i, L) cin >> A[i];
    
    vvvl dp(L+1, vvl(3, vl(3, LINF))); // i, st, o-e changed or closed if st == 0
    rep(st, 3) dp[0][st][0] = 0;
    rep(i, L){
        // zero
        chmin(dp[i+1][0][0], dp[i][0][0]+A[i]); // not open
        rep(st, 3) rep(ch, 3){ // close
            chmin(dp[i+1][0][1], dp[i][st][ch]+A[i]);
        }
        
        // odd
        chmin(dp[i+1][1][0], dp[i][0][0]+1-A[i]%2);
        chmin(dp[i+1][1][0], dp[i][1][0]+1-A[i]%2);
        
        chmin(dp[i+1][1][1], dp[i][1][1]+1-A[i]%2);
        chmin(dp[i+1][1][1], dp[i][2][0]+1-A[i]%2);
        
        
        // even
        ll ae = A[i] == 0 ? 2 : A[i]%2;
        chmin(dp[i+1][2][0], dp[i][0][0]+ae);
        chmin(dp[i+1][2][0], dp[i][2][0]+ae);
        
        chmin(dp[i+1][2][1], dp[i][2][1]+ae);
        chmin(dp[i+1][2][1], dp[i][1][0]+ae);
        
        chmin(dp[i+1][2][2], dp[i][1][1]+ae);
        chmin(dp[i+1][2][2], dp[i][2][2]+ae);
    }
    
    ll ans = LINF;
    rep(st, 3) rep(ch, 3){
        chmin(ans, dp[L][st][ch]);
    }
    cout << ans << endstr;
    return 0;
}


Measured memory_bytes: 40832