#include <bits/stdc++.h>
using namespace std;
#include <atcoder/all>
using namespace atcoder;

using ll = long long;

int main() {
	int N; ll K;
	cin >> N >> K;
	vector<int> A(N);
	for(int i = 0; i < N; ++i) cin >> A[i];
	A.insert(A.begin(), 0);
	A.push_back(0);
	N += 2;
	
	vector<int> P(N);
	iota(P.begin(), P.end(), 0);
	sort(P.rbegin(), P.rend(), [&](const int i, const int j) {return A[i] < A[j];});
	
	vector<ll> cnt(N + 1, 0), val(N, -1);
	dsu uf(N);
	auto unite = [&](int x, int y, int t) {
		x = uf.leader(x), y = uf.leader(y);
		if(x == y) return;
		
		cnt[uf.size(x)] += (val[x] - t);
		cnt[uf.size(y)] += (val[y] - t);
		val[x] = val[y] = t;
		uf.merge(x, y);
	};
	
	for(auto i : P) {
		val[i] = A[i];
		if(0 <= i - 1 and A[i - 1] >= A[i]) unite(i - 1, i, A[i]);
		if(i + 1 < N and A[i + 1] > A[i]) unite(i, i + 1, A[i]);
	}
	
	ll ans = 0;
	for(int i = 0; i < N - 1; ++i) ans += abs(A[i] - A[i + 1]);
	for(int i = 1; i <= N; ++i) {
		ll t = min(K / i, cnt[i]);
		ans -= t * 2;
		K -= t * i;
	}
	
	cout << ans << "\n";
}