#include <bits/stdc++.h>
#include <ext/pb_ds/tree_policy.hpp>
#include <ext/pb_ds/assoc_container.hpp>
using namespace std;
using namespace __gnu_pbds;
typedef long long ll;
typedef long double ld;
typedef complex<ld> cd;
typedef pair<int, int> pi;
typedef pair<ll,ll> pl;
typedef pair<ld,ld> pd;
typedef vector<int> vi;
typedef vector<ld> vd;
typedef vector<ll> vl;
typedef vector<pi> vpi;
typedef vector<pl> vpl;
typedef vector<cd> vcd;
template <class T> using Tree = tree<T, null_type, less<T>, rb_tree_tag,tree_order_statistics_node_update>;
#define FOR(i, a, b) for (int i=a; i<(b); i++)
#define F0R(i, a) for (int i=0; i<(a); i++)
#define FORd(i,a,b) for (int i = (b)-1; i >= a; i--)
#define F0Rd(i,a) for (int i = (a)-1; i >= 0; i--)
#define sz(x) (int)(x).size()
#define mp make_pair
#define pb push_back
#define f first
#define s second
#define lb lower_bound
#define ub upper_bound
#define all(x) x.begin(), x.end()
const int MOD = 1000000007;
const ll INF = 1e18;
const int MX = 1000001;
int N;
int par[MX], L[MX], R[MX], h[MX];
int norm(int x) { return (x%N+N)%N; }
int get(int x) {
if (par[x] != x) par[x] = get(par[x]);
return par[x];
}
pi tri(int x) {
x = get(norm(x));
return {h[x],x};
}
void uniteLeft(int a, int b) {
R[a] = R[b];
par[b] = a;
}
void uniteRight(int a, int b) {
L[a] = L[b];
par[b] = a;
}
int mag(int a, int b) {
if (b < a) b += N;
return b-a+1;
}
int k,ans, posi[MX];
int main() {
ios_base::sync_with_stdio(0); cin.tie(0);
cin >> N >> k;
F0R(i,N) {
cin >> h[i];
L[i] = R[i] = par[i] = i;
}
vi v(N); F0R(i,N) v[i] = i;
sort(all(v),[](int a, int b) { if (h[a] != h[b]) return h[a] < h[b]; return a < b; });
F0R(i,sz(v)-1) {
auto a = v[i];
// cout << a.f << " " << a.s << " " << L[a.s] << " " << R[a.s] << " " << mag(L[a.s],R[a.s]) << "\n";
pi z1 = tri(L[a]-1);
pi z2 = tri(R[a]+1);
int m = mag(L[a],R[a]);
if (z1 < z2) {
posi[m] += z1.f-h[a];
uniteLeft(z1.s,a);
} else {
posi[m] += z2.f-h[a];
uniteRight(z2.s,a);
}
posi[m] = min(posi[m],MOD);
}
FOR(i,1,N) {
int K = min(k/i,posi[i]);
ans += K; k -= i*K;
}
cout << 2*ans;
}
/* Look for:
* the exact constraints (multiple sets are too slow for n=10^6 :( )
* special cases (n=1?)
* overflow (ll vs int?)
* array bounds
*/
