#include <bits/stdc++.h>
#define fs first
#define sc second
#define ls (u << 1)
#define rs (u << 1 | 1)
#define mid ((l + r) >> 1)
#define lc ls, l, mid
#define rc rs, mid + 1, r
#define rep(i, l, r) for (int i = (l); i <= (r); ++i)
#define per(i, r, l) for (int i = (r); i >= (l); --i)
#define gc getchar
#define pc putchar
#define low (S & -S)

using namespace std;
using pii = pair<int, int>;
using vi = vector<int>;
using ll = long long;

const int maxn = 25;
const bool multidata = 0;

template<typename T = int>
T read() {
	T x = 0, f = 1; char c = gc();
	while (c < '0' || c > '9') { if (c == '-') f = -f; c = gc(); }
	while (c >= '0' && c <= '9') x = x * 10 + c - '0', c = gc();
	return x * f;
}

template<typename T = int>
void write(T x) {
	if (x < 0) pc('-'), x = -x;
	if (x < 10) return void (pc(x + '0'));
	write<T>(x / 10), pc(x % 10 + '0');
}

int n;
int a[maxn], b[maxn];
int f[1 << maxn];

void solve(int * a, int n, ll sum) {
	if (n == 1) {
		if (!sum) ++(*a);
		return;
	}
	solve(a, n >> 1, sum);
	rep(i, (n >> 1), n - 1) a[i] = max(a[i], a[i - (n >> 1)]);
	solve(a + (n >> 1), n >> 1, sum + b[__lg(n) - 1]);
}

void fake_main() {
	n = read();
	rep(i, 1, n) a[i] = read();
	rep(i, 0, n) b[i] = a[i + 1] - a[i];
	++n;
	solve(f, 1 << n, 0);
	write(n - f[(1 << n) - 1] + 1);
}

signed main() {
//	freopen("cloud.in", "r", stdin);
//	freopen("cloud.out", "w", stdout);
	int T = multidata ? read() : 1;
	while (T--) fake_main();
	return 0;
}