#include <bits/stdc++.h>
#define m_p make_pair
#define pw2(x) (1LL<<x)
#define all(x) (x).begin(),(x).end()
#define rall(x) (x).rbegin(),(x).rend()
#define f first
#define sz(x) (int)x.size()
#define len(x) (int)x.size()
#define pb push_back
#define s second
#define vec vector
#define REP(i, a,b) for(int i=(a);i<(b);i++)
#define REPD(i, a,b) for(int i=(a);i>=(b);--i)
#define file "name"
#define fi first
#define se second
using namespace std;
template<class T> bool umin(T &a,const T &b){return (a>b?a=b,1:0);}
template<class T> bool umax(T &a,const T &b){return (a<b?a=b,1:0);}
typedef long long ll;
typedef pair<int,int> pii;
typedef long double ld;
typedef pair<long long, long long> pll;
#define sim template < class c
#define ris return * this
#define dor > debug & operator <<
#define eni(x) sim > typename \
enable_if<sizeof dud<c>(0) x 1, debug&>::type operator<<(c i) {
sim > struct rge { c b, e; };
sim > rge<c> range(c i, c j) { return rge<c>{i, j}; }
sim > auto dud(c* x) -> decltype(cerr << *x, 0);
sim > char dud(...);
struct debug {
#ifndef LOCAL
~debug() { cerr << endl; }
eni(!=) cerr << boolalpha << i; ris; }
eni(==) ris << range(begin(i), end(i)); }
sim, class b dor(pair < b, c > d) {
ris << "(" << d.first << ", " << d.second << ")";
}
sim dor(rge<c> d) {
*this << "[";
for (auto it = d.b; it != d.e; ++it)
*this << ", " + 2 * (it == d.b) << *it;
ris << "]";
}
#else
sim dor(const c&) { ris; }
#endif
};
#define imie(...) " [" << #__VA_ARGS__ ": " << (__VA_ARGS__) << "] "
void INPUT(bool F=0){
ios_base::sync_with_stdio(false);cin.tie(0);cout.tie(0);
if(F){
freopen(file".in","r",stdin);
freopen(file".out","w",stdout);
}
}
struct myset{
multiset<__int128> st;
__int128 ta=0;
void add(__int128 x){
x-=ta;
st.insert(x);
}
__int128 gb(){
assert(sz(st));
return *st.rbegin()+ta;
}
__int128 gf(){
assert(sz(st));
return *st.begin()+ta;
}
};
signed main(){
INPUT();
ios_base::sync_with_stdio(0), cin.tie(0), cout.tie(0);
myset l,r;
int n,t;
cin>>n>>t;
__int128 ans=9e18;
__int128 k=0,b=0;
auto insrt=[&](ll x){
l.add(x);l.add(x);k++;b-=x;
while(sz(l.st)!=sz(r.st)){
ll y=l.gb();l.st.erase(--l.st.end());
r.add(y);
}
};
auto fix=[&](){
while(r.gf()<l.gb()){
ll x=l.gb();ll y=r.gf();
l.st.erase(--l.st.end());r.st.erase(r.st.begin());
l.add(y);r.add(x);
}
};
for(int i=0;i<n;i++){
int x;
cin>>x;
l.ta-=t;r.ta+=t;b-=1ll*sz(r.st)*t;
insrt(x);fix();
// for(auto &q : l.st) debug()<<imie(q+l.ta);
// for(auto &q : r.st) debug()<<imie(q+r.ta);
// cout<<endl;
// debug()<<imie(k);
}
// debug()<<imie(b)imie(k);
vec<ll>xs;
while(sz(l.st)) xs.pb(l.gf()),l.st.erase(l.st.begin());
while(sz(r.st)) xs.pb(r.gf()),r.st.erase(r.st.begin());
reverse(all(xs));
for(auto &x : xs){
umin(ans,(__int128)k*x+b);
k--;b+=x;
}
ll rl=ans;
cout<<rl;
return 0;
}
/*
#fwxpd bf
fwxpdbf
dpinbmcrfwxpdbf
*/
