#include <bits/stdc++.h>
using namespace std;
typedef signed long long ll;

const ll MAXN = 2*1e5 + 7;
const ll MAXC = 1e12 + 7;
const ll MAXH = 1e6 + 7;

ll n, c;
vector<ll> h;

ll dp[MAXN];

deque<pair<ll, ll>> q;

double i(const pair<ll, ll>& a, const pair<ll, ll> b){ /// interesect
    return ((double)(b.second - a.second))/(a.first - b.first);
}
double e(const pair<ll, ll>& line, double x){ /// evaluate
    return line.first * x  + line.second;
}

void add(pair<ll, ll> nw){
    if(q.size() < 2){ q.push_back(nw); return; }
    pair<ll, ll> a = q.back();
    pair<ll, ll> b = *prev(q.end(), 2);
    while(q.size() >= 2 && (i(a, b) > i(b, nw))){
        q.pop_back();
        a = b;
        b = *prev(q.end(), -2);
    }
    q.push_back(nw);
}
ll query(double x){
    if(q.size() < 2){ return e(q.front(), x); }
    pair<ll, ll> a = q.front();
    pair<ll, ll> b = *next(q.begin());
    while(q.size() >= 2 && i(a, b) < x){
        q.pop_front();
        a = b;
        b = *next(q.begin());
    }
    return e(q.front(), x);
}

int main(){
    cin >> n >> c;
    h.resize(n);
    for(ll i = 0; i < n; i++){
        cin >> h[i];
    }

    for(ll i = 0; i < n; i++){
///        h[i]*h[i] - 2*h[i]*h[j] + h[j]*h[j] + dp[j] + c;
        if(i == 0){ dp[i] = 0; }
        else{
            dp[i] = query(h[i]) + h[i]*h[i] + c;
        }

        pair<ll, ll> newLine = {-2*h[i], h[i]*h[i] + dp[i]};
        add(newLine);
    }

    cout << dp[n-1] << '\n';

    return 0;
}