#include <bits/stdc++.h>
#define forn(i, n) for (tint i = 0; i < tint(n); i++)
#define forsn(i, s, n) for (tint i = s; i < tint(n); i++)
#define dforn(i, n) for (tint i = tint(n) - 1; i >= 0; i--)
#define dforsn(i, s, n) for (tint i = tint(n) - 1; i >= s; i--)
#define sz(x) tint(x.size())
#define all(x) x.begin(), x.end()
#define rall(x) x.rbegin(), x.rend()
#define DBG(x) cerr << #x << " = " << x << endl
using namespace std;
using tint = long long;
using vi = vector<tint>;
using pii = pair<tint, tint>;
inline void fastIO()
{
ios_base::sync_with_stdio(false);
cin.tie(NULL);
}
inline string YN(bool x, string y = "YES", string n = "NO") { return (x ? y : n); }
template <typename T>
inline void chmax(T &lhs, T rhs)
{
lhs = max(lhs, rhs);
}
template <typename T>
inline void chmin(T &lhs, T rhs)
{
lhs = min(lhs, rhs);
}
template <typename T, typename U>
ostream &operator<<(ostream &os, const pair<T, U> &p)
{
os << "(" << p.first << ", " << p.second << ")";
return os;
}
template <typename T>
ostream &operator<<(ostream &os, const vector<T> &v)
{
os << "[";
forn(i, sz(v))
{
if (i > 0)
os << ", ";
os << v[i];
}
os << "]";
return os;
}
template <typename T, size_t N>
ostream &operator<<(ostream &os, const array<T, N> &v)
{
os << "[";
forn(i, N)
{
if (i > 0)
os << ", ";
os << v[i];
}
os << "]";
return os;
}
int main()
{
fastIO();
tint n, k;
cin >> n >> k;
vi arr;
tint curr = 0, prevSign = -1, start = 0, pos = 0;
forn(i, n)
{
tint el;
cin >> el;
bool sign = (el >= 0);
if (prevSign != -1 && prevSign != sign)
{
arr.push_back(curr);
pos += (curr > 0);
start += curr * (curr > 0);
curr = 0;
}
curr += el;
prevSign = sign;
}
pos += (curr > 0);
start += curr * (curr > 0);
arr.push_back(curr);
arr.push_back(0);
n = sz(arr);
auto f = [&](tint lam)
{
tint ret = start - lam * pos, left = 0;
forn(i, n - 1)
{
if (arr[i] <= 0)
continue;
ret += max(0LL, lam - min(arr[i], -arr[i + 1]));
}
return -(ret + lam * k);
};
tint l = 0, r = 1e9;
while (r - l > 2)
{
tint m1 = l + (r - l) / 3;
tint m2 = r - (r - l) / 3;
tint f1 = f(m1);
tint f2 = f(m2);
if (f1 < f2)
l = m1;
else
r = m2;
}
tint ans = -1e9;
forsn(i, l, r + 1) chmax(ans, f(i));
cout << -ans << "\n";
}
