#include <bits/stdc++.h>
#define fi first
#define se second
#define ll long long
#define pl pair<ll, ll>
#define pi pair<int, int>
#define minpq priority_queue<ll, vector<ll>, greater<ll>>
using namespace std;

#if 1
void __print(int x) {cerr << x;}
void __print(long x) {cerr << x;}
void __print(long long x) {cerr << x;}
void __print(unsigned x) {cerr << x;}
void __print(unsigned long x) {cerr << x;}
void __print(unsigned long long x) {cerr << x;}
void __print(float x) {cerr << x;}
void __print(double x) {cerr << x;}
void __print(long double x) {cerr << x;}
void __print(char x) {cerr << '\'' << x << '\'';}
void __print(const char *x) {cerr << '\"' << x << '\"';}
void __print(const string &x) {cerr << '\"' << x << '\"';}
void __print(bool x) {cerr << (x ? "true" : "false");}
template<typename T, typename V>
void __print(const pair<T, V> &x) {cerr << '{'; __print(x.first); cerr << ','; __print(x.second); cerr << '}';}
template<typename T>
void __print(const T &x) {int f = 0; cerr << '['; for (auto &i: x) cerr << (f++ ? "," : ""), __print(i); cerr << "]";}
void _print() {cerr << endl << flush;}
template <typename T, typename... V>
void _print(T t, V... v) {__print(t); if (sizeof...(v)) cerr << ", "; _print(v...);}
#define debug(x...) cerr << "*["<<__LINE__<<"]\t"<< #x << " = "; _print(x)
#endif

const ll mod = 1e9 + 7;

template<typename T> bool chkmin(T &a, T b){return (b < a) ? a = b, 1 : 0;}
template<typename T> bool chkmax(T &a, T b){return (b > a) ? a = b, 1 : 0;}
ll gcd(ll a, ll b) {if(b == 0){return a;} return gcd(b, a % b);}

__int128 read_int128() {
    string str;
    cin >> str;

    __int128 x = 0, f = 1;
    if (str[0] == '-') {
        f = -1;
        str = str.substr(1);
    }

    for (char c : str) {
        x = x * 10 + (c - '0');
    }
    return x * f;
}

ostream& operator<<(ostream& dest, __int128_t value){
    ostream::sentry s( dest );
    if (s) {
        __uint128_t tmp = value < 0 ? -value : value;
        char buffer[128];
        char* d = std::end(buffer);
        do{
            -- d;
            *d = "0123456789"[tmp % 10];
            tmp /= 10;
        } while (tmp != 0);
        if (value < 0) {
            -- d;
            *d = '-';
        }
        int len = end(buffer) - d;
        if (dest.rdbuf()->sputn(d, len) != len) {
            dest.setstate(ios_base::badbit);
        }
    }
    return dest;
}

int main(){
	ios::sync_with_stdio(false);
	cin.tie(0);
	int n; cin >> n;
	vector<__int128_t> a(n); for (int i = 0; i < n; i ++) a[i] = read_int128();
	vector<int> b(n);
	for (int i = 0; i < n; i ++){
		for (int j = 0; j <= 100; j ++) if (a[i] & ((__int128_t)1 << j)) b[i] = j;
	}
	int dp[n + 1][n + 1]; memset(dp, 0, sizeof(dp));
	for (int i = 0; i < n; i ++) dp[i][i] = b[i];	
	for (int len = 2; len <= n; len ++){
		for (int i = 0; i < n; i ++){
			int j = i + len - 1;
			for (int k = 1; k < len; k ++){
				int l = i + k - 1;
				if (dp[i][l] == dp[l + 1][j]) chkmax(dp[i][j], dp[i][l] + 1);
				else chkmax(dp[i][j], max(dp[i][l], dp[l + 1][j]));
			}
		}
	}
	cout << ((__int128_t)1 << dp[0][n - 1]) << '\n';
}