#include <bits/stdc++.h>
#define ll long long
#define pb push_back

using namespace std;

int main()
{
    ios_base::sync_with_stdio(false);
	cin.tie(nullptr);
	cout.tie(nullptr);

	int n;
	cin >> n;

	vector<int> a(n);
	for(int i=0; i<n; i++) cin >> a[i];

	bool ok = true;
	for(int i=1; i<n; i++) if(a[i] < a[i-1]) ok = false;

	if(ok)
    {
        cout << 0;
        return 0;
    }

    int cnt = 0, l = 0, r = n - 1;
    while(l <= r)
    {
        if(cnt % 2 == 0)
        {
            int m = min(a[l], a[r]);

            while(a[l] >= m || a[r] >= m && l <= r)
            {
                if(a[l] >= a[r]) r--;
                else l++;
            }

            cnt++;
        }
        else
        {
            int M = min(a[l], a[r]);

            while(a[l] <= M || a[r] <= M && l <= r)
            {
                if(a[l] <= a[r]) r--;
                else l++;
            }

            cnt++;
        }
    }

    int ans = 0, now = 1;
    while(now < cnt)
    {
        now *= 2;
        ans++;
    }

    cout << ans + 1;
}