#include"mountains.h"
#include<bits/stdc++.h>
using namespace std;
const int N = 2010;
int y[N];
int f[N][N];
bool pd(int a,int b,int c) {
// ((y[a] - y[b]) / (a - b)) > ((y[a] - y[c]) / (a - c));
return 1ll * (y[a] - y[b]) * (a - c) > 1ll * (y[a] - y[c]) * (a - b);
}
int solve(int l,int r) {
if (f[l][r]) return f[l][r];
if (l > r) return 0;
if (l == r) return 1;
int pos = -1, mx = -1;
for (int i=l; i<=r; ++i)
if (y[i] > mx) pos = i, mx = y[i];
int ans1 = solve(l, pos - 1) + solve(pos + 1, r);
int ans2 = 0, L = pos - 1;
for (int i=pos-2; i>=1; --i) {
if (pd(i, L, pos)) continue;
ans2 += solve(i + 1, L - 1);
L = i;
}
return f[l][r] = max(ans1, ans2);
}
int maximum_deevs(vector<int> A) {
int n = A.size();
for (int i=1; i<=n; ++i) y[i] = A[i - 1];
return solve(1, n);
}
