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

using ll = long long;
using pii = pair<int, int>;
using pll = pair<ll,ll>;
using vb = vector<bool>;
using vi = vector<int>;
using vll = vector<long long>;
using vvi = vector<vi>;
using vvll = vector<vll>;
using vpii = vector<pii>;
using vpll = vector<pll>;
using vs = vector<string>;
using vc = vector<char>;
#define rep(i, n) for (int i = 0; i < (int)(n); i++)
#define all(a) (a).begin(), (a).end()
#define uniq(v) sort(all(v)), (v).erase(unique(all(v)),(v).end())
#define lb(v,x) int(lower_bound(all(v),(x))-(v).begin())
#define ub(v,x) int(upper_bound(all(v),(x))-(v).begin())
#define rrep(i,n) for(int i = (int)(n) - 1; i>=0; i--)
#define rep1(i,n) for(int i=1; i <=(int)(n);i++)
#define reps(i,s,n) for(int i=(int)(s);i<(int)(n); i++)
#define koz " "
#define tor "\n"
template<class T> using min_pq = priority_queue<T, vector<T>, greater<T>>;
template<class T> bool chmin(T& a, const T& b){if(b<a){a=b;return true;}return false;}
template<class T> bool chmax(T& a, const T& b){if(a<b){a=b;return true;}return false;}
template<typename T, typename U> T ceil(T x, U y){
    assert(y!=0);
    if(y<0) x=-x,y=-y;
    return (x>0 ? (x+y-1)/y : x/y);
}
template<typename T, typename U> T floor(T x, U y){
    assert(y!=0);
    if(y<0) x=-x,y=-y;
    return (x>0 ? x/y : (x-y+1)/y);
}
template<typename T> int popcnt(T x){return __builtin_popcountll(x);}

const int dx[]={1,0,-1,0,1,1,-1,-1};
const int dy[]={0,1,0,-1,1,-1,1,-1};

const int INF = 1045141919;
const ll LINF = 3643648101145141919;

void solve(){
    ll n,k;
    cin >> n >> k;
    vll a(n);
    rep(i,n) cin >> a[i];
    ll ok=LINF,ng=-1;
    auto judge=[&](ll x)->bool{
        ll need=0;
        rep(i,n){
            if(x<a[i]) need+=a[i]-x;
        }
        if(need<=k) return true;
        else return false;

    };
    while(abs(ok-ng)>1){
        ll mid=ng+(ok-ng)/2;
        if(judge(mid)) ok=mid;
        else ng=mid;
    }
    ll cnt=0;
    rep(i,n){
        if(a[i]>ok) cnt+=a[i]-ok;
    }
    ll rem=k-cnt;
    vll b(n);
    rep(i,n) b[i]=min(a[i],ok);
    vll c;
    c.push_back(0);
    rep(i,n) c.push_back(b[i]);
    c.push_back(0);
    min_pq<int> pq;
    int now=0;
    bool ok2=false;
    for(int i=1;i<=n;){
        int j=i;
        while(j<=n&&c[j]==c[i]) j++;
        if(c[i-1]<c[i]&&c[i]>c[j]) rep(k,min(c[i]-c[j],c[i]-c[i-1])) pq.push(j-i);
        i=j;
    }
    ll ans=0;
    rep(i,n)if(i) ans+=abs(b[i]-b[i-1]);
    ans+=b[0]+b[n-1];
    while(rem&&!pq.empty()){
        int v=pq.top();
        if(v>rem){
            break;
        }
        rem-=v;
        pq.pop();
        ans-=2;
    }
    cout << ans << tor;

}

int main() {
    cin.tie(nullptr);
    ios::sync_with_stdio(false);
    cout << fixed << setprecision(16);

    int _ = 1;
    //cin >> _;
    while(_--) solve();
    
}