#include <bits/stdc++.h>

using namespace std;

using ll = long long;
using ull = unsigned long long;

#define REP(i,n) for(long long i = 0; i < (n); i++)
#define FOR(i, m, n) for(long long i = (m);i < (n); ++i)
#define ALL(obj) (obj).begin(),(obj).end()

template<class T> using V = vector<T>;
template<class T, class U> using P = pair<T, U>;

const ll MOD = (ll)1e9 + 7;
const ll MOD2 = 998244353;
const ll LLINF = (ll)1e18;
const ll INTINF = (ll)1e9;
const long double PI = 3.1415926535897932384626433;

template <class T> void corner(bool flg, T hoge) {if (flg) {cout << hoge << endl; exit(0);}}
template <class T, class U>ostream &operator<<(ostream &o, const map<T, U>&obj) {o << "{"; for (auto &x : obj) o << " {" << x.first << " : " << x.second << "}" << ","; o << " }"; return o;}
template <class T>ostream &operator<<(ostream &o, const set<T>&obj) {o << "{"; for (auto itr = obj.begin(); itr != obj.end(); ++itr) o << (itr != obj.begin() ? ", " : "") << *itr; o << "}"; return o;}
template <class T>ostream &operator<<(ostream &o, const multiset<T>&obj) {o << "{"; for (auto itr = obj.begin(); itr != obj.end(); ++itr) o << (itr != obj.begin() ? ", " : "") << *itr; o << "}"; return o;}
template <class T>ostream &operator<<(ostream &o, const vector<T>&obj) {o << "{"; for (int i = 0; i < (int)obj.size(); ++i)o << (i > 0 ? ", " : "") << obj[i]; o << "}"; return o;}
template <class T, class U>ostream &operator<<(ostream &o, const pair<T, U>&obj) {o << "{" << obj.first << ", " << obj.second << "}"; return o;}
template <template <class tmp>  class T, class U> ostream &operator<<(ostream &o, const T<U> &obj) {o << "{"; for (auto itr = obj.begin(); itr != obj.end(); ++itr)o << (itr != obj.begin() ? ", " : "") << *itr; o << "}"; return o;}
void print(void) {cout << endl;}
template <class Head> void print(Head&& head) {cout << head;print();}
template <class Head, class... Tail> void print(Head&& head, Tail&&... tail) {cout << head << " ";print(forward<Tail>(tail)...);}
template <class T> void chmax(T& a, const T b){a=max<T>(a,b);}
template <class T> void chmin(T& a, const T b){a=min<T>(a,b);}
void YN(bool flg) {cout << ((flg) ? "YES" : "NO") << endl;}
void Yn(bool flg) {cout << ((flg) ? "Yes" : "No") << endl;}
void yn(bool flg) {cout << ((flg) ? "yes" : "no") << endl;}

int main() {
	while(1){
		int N; cin >> N;
		if(N==0) return 0;
		V<int> X(N);
		REP(i,N) cin >> X[i];
		V<P<int,int>> v;
		v.push_back({X[0],1});
		for(int i = 1; i < N; ++i){
			if(v.back().first==X[i]) v.back().second++;
			else v.push_back({X[i],1});
		}
		int ans = N;
		for(int i = 0; i < v.size(); ++i){
			if(v[i].second !=1) continue;
			int cnt = 1;
			for(int j = 1; 0 <= i - j && i + j < v.size(); ++j){
				if(v[i-j].first!=v[i+j].first) break;
				if(v[i-j].second+v[i+j].second<4) break;
				cnt += v[i-j].second+v[i+j].second;
			}
			chmin(ans,N-(cnt!=1?cnt:0));
		}
		for(int i = 1; i < v.size() - 1; ++i){
			if(v[i].second !=3) continue;
			int cnt = 4;
			if(v[i-1].first == v[i+1].first && v[i-1].second+v[i+1].second - 1 >= 4){
				cnt += v[i-1].second+v[i+1].second - 1;
				for(int j = 2; 0 <= i - j && i + j < v.size(); ++j){
					if(v[i-j].first!=v[i+j].first) break;
					if(v[i-j].second+v[i+j].second<4) break;
					cnt += v[i-j].second+v[i+j].second;
				}
			}
			chmin(ans,N-cnt);
		}
		cout << ans << endl;
	}
	return 0;
}



Measured memory_bytes: 3204