#include "bits/stdc++.h"
#define YESNO OUT(three(solve(),"YES","NO"))
#define YesNo OUT(three(solve(),"Yes","No"))
#define WL(A,B) OUT(three(solve(),A,B))
#define ECHO OUT(solve())
#define three(A,B,C) ((A)?(B):(C))
#define FOR(i,a,b)  for(LL i=(a);i< (LL)(b);i++)
#define EFOR(i,a,b) for(LL i=(a);i<=(LL)(b);i++)
#define RFOR(i,a,b) for(LL i=(b);i>=(LL)(a);i--)
#define REP(i,b) FOR(i,zero,b)
#define rep REP
#define EREP(i,b) EFOR(i,zero,b)
#define RREP(i,b) RFOR(i,b,zero)
#define ALL(c) c.begin(),c.end()
#define UNIQUE(c) sort(ALL(c));c.erase(unique(ALL(c)),c.end())
#define MAX(c) (*max_element(ALL(c)))
#define MIN(c) (*min_element(ALL(c)))
#define MP make_pair
#define FI first
#define SE second
#define SI(x) (LL(x.size()))
#define PB push_back
#define DEBUG(a) OUT(a)
#define DEBUG2(a,b) OUT2(a,b)
#define cat cout << __LINE__ << endl
#define OUT(a) cout << (a) << endl
#define OUT2(a,b) cout << (a) <<" "<<(b) << endl
#define zero 0LL
#define all ALL
#define pb emplace_back
#define eb pb
#define int long long
using namespace std;
template<typename T> inline void maximize(T &a, T b) { a = max(a, b); }
template<typename T> inline void minimize(T &a, T b) { a = min(a, b); }
template<typename T> inline bool middle(T a, T b, T c) { return b <= a && a <= c; }
template<class T> inline bool MX(T &l, const T &r) { return l < r ? l = r, 1 : 0; }
template<class T> inline bool MN(T &l, const T &r) { return l > r ? l = r, 1 : 0; }
template<class T> inline bool chmax(int a, int b, T c, T d) { return c > d ? a : b; }
template<class T> inline bool chmin(int a, int b, T c, T d) { return c > d ? a : b; }
typedef int LL;
typedef double ld;
typedef int ut;
typedef vector<ut> VI;
typedef vector<VI> VII;
typedef pair<ut, ut> pr;
typedef pair<ut, pr> ppr;
typedef vector<pr> Vpr;
typedef vector<ppr> Vppr;
typedef tuple<int, int, int, int> tapu;
typedef vector<tapu> Vtapu;
typedef priority_queue<ut, VI, greater<LL> > PQ;
inline void outputVI(VI x) { REP(i, SI(x)) { cout << three(i, " ", "") << x[i]; }OUT(""); }
const int SIZE1 = 1e6 + 1000;
const int SIZE2 = 4010;
const int SIZE3 = 430;
const int SIZE = SIZE1;
const int MAPSIZE = 40;
const LL p =998244353;
const LL INF = 1LL << 30;
const long double EPS = 1e-7;
const LL inf = 1000000000;
typedef pair<ld, ut> pld;
ut N, M, K, L, Q,  H, W, R;
VI edges[SIZE];
LL vals[SIZE], answer = zero;
//LL maps[SIZE2][SIZE2];
LL A[SIZE],B[SIZE],C[SIZE],D[SIZE],E[SIZE];
LL DP[SIZE][5];
LL solve() {
	LL L;
	cin >> L;
	LL ans = INF;
	EFOR(i, 1, L) cin >> A[i];
	EFOR(i,1,L){
		REP(j, 5) {
			DP[i][j] = INF;
			if (j)
				DP[i][j] = DP[i][j - 1];
			if (j == 0) MN(DP[i][j],DP[i - 1][j] + A[i]);
			if (j == 1) MN(DP[i][j], DP[i - 1][j]+max(2 - A[i],A[i]%2));
			if (j == 2) MN(DP[i][j], DP[i - 1][j] + max(1-A[i], (A[i] + 1) % 2));
			if (j == 3) MN(DP[i][j], DP[i - 1][j] + max(2 - A[i], A[i] % 2));
			if (j == 4) MN(DP[i][j], DP[i - 1][j] + A[i]);
	//		cout << i << " " << j << " " << DP[i][j] << endl;
		}
	}
	return DP[L][4];
}




//!!!!!!!!!!!!!!!!!!!実装を詰める!!!!!!!!!!!!!!!!!!!!!!!!!
signed main() {

	ios_base::sync_with_stdio(false);
	cout << fixed << setprecision(0);
	cout << solve() << endl;
	
	//cin >> N;
	return 0;

}

Measured memory_bytes: 36096