#include <bits/stdc++.h>
 
using namespace std; 
 
typedef long long ll; 
typedef pair<int, int> ii; 
 
const ll LINF = 1e18; 
const int INF = 1e9;
 
int n, k;  
int h[12], pref_mx[12], suf_mx[12]; 
ll best; 
 
void backtrack(int i, int k) {
	if (i == n) {
		pref_mx[0] = h[0]; 
		for (int i = 1; i < n; i++) pref_mx[i] = max(pref_mx[i - 1], h[i]); 
 
		suf_mx[n - 1] = h[n - 1]; 
		for (int i = n - 2; i >= 0; i--) suf_mx[i] = max(suf_mx[i + 1], h[i]); 
 
		ll ans = 0; 
		for (int i = 1; i + 1 < n; i++) {
			ans += max(0, min(pref_mx[i - 1], suf_mx[i + 1]) - h[i]); 
		}
 
		best = max(best, ans); 
		return; 
	}
 
	for (int j = 0; j <= k; j++) {
		h[i] += j;  
		backtrack(i + 1, k - j); 
		h[i] -= j;  
	}
} 
// Gọi x(i) là số đồng Phúc dùng cho cột thứ i 
// Ta có x(1) + x(2) + ... + x(n) <= k (1)
// Số nghiệm của (1) <=> x(1) + x(2) + ... + x(n) + x(n + 1) = k   
// => C(k + n, n) (Chia kẹo Euler)
// => Độ phức tạp: O(C(k + n, n) * n)
 
int main() {
	ios::sync_with_stdio(false); 
	cin.tie(nullptr); 
	cin >> n >> k; 
 
	for (int i = 0; i < n; i++) cin >> h[i]; 
 
	best = 0; 
	backtrack(0, k); 
 
	cout << best << '\n'; 
}
 

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