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

#define NDEBUG
#ifdef DEBUG
#include "../cout11.h"
#undef NDEBUG
#endif
#include <cassert>

#ifdef DEBUG
#define debug(fmt, ...) fprintf(stderr, fmt, __VA_ARGS__)
#else
#define debug(fmt, ...)
#endif

typedef long long ll;
typedef long double Double;
typedef unsigned long long ull;
typedef pair<int,int> ii;
typedef pair<ll,ll> llll;
typedef pair<double,double> dd;

typedef vector<int> vi;
typedef vector<vector<int>> vvi;
typedef vector<ii> vii;
typedef vector<vector<ii>> vvii;
typedef vector<ll> vll;
typedef vector<vector<ll>> vvll;
typedef vector<llll> vllll;
typedef vector<bool> vb;
typedef vector<string> vs;
typedef vector<double> vd;
typedef vector<long double> vD;

#define sz(a)  int((a).size())
#define pb  push_back
#define eb  emplace_back
#define FOR(var,from,to) for(int var=(from);var<=(to);++var)
#define rep(var,n)  for(int var=0;var<(n);++var)
#define rep1(var,n)  for(int var=1;var<=(n);++var)
#define repC2(vari,varj,n)  for(int vari=0;vari<(n)-1;++vari)for(int varj=vari+1;varj<(n);++varj)
#define repC3(vari,varj,vark,n)  for(int vari=0;vari<(n)-2;++vari)for(int varj=vari+1;varj<(n)-1;++varj)for(int vark=varj+1;vark<(n);++vark)
#define ALL(c)  (c).begin(),(c).end()
#define RALL(c)  (c).rbegin(),(c).rend()
#define tr(i,c)  for(auto i=(c).begin(); i!=(c).end(); ++i)
#define found(s,e)  ((s).find(e)!=(s).end())
#define mset(arr,val)  memset(arr,val,sizeof(arr))
#define mid(x,y) ((x)+((y)-(x))/2)
#define IN(x,a,b) ((a)<=(x)&&(x)<=(b))
#define cons make_pair

template<class T> inline void amin(T & a, T const & b) { a = min(a, b); }
template<class T> inline void amax(T & a, T const & b) { a = max(a, b); }
template<typename X, typename T> auto vectors(X x, T a) { return vector<T>(x, a); }
template<typename X, typename Y, typename Z, typename... Zs> auto vectors(X x, Y y, Z z, Zs... zs) { auto cont = vectors(y, z, zs...); return vector<decltype(cont)>(x, cont); }


ll gcd(ll a, ll b) { while(a) swap(a, b%=a); return b; }
template <typename T>
T mod(T a, T b) { return ((a % b) + b) % b; }

const ll MOD=1000000007LL;

ll ADD(ll x, ll y) { return (x+y) % MOD; }
ll SUB(ll x, ll y) { return (x-y+MOD) % MOD; }
ll MUL(ll x, ll y) { return x*y % MOD; }
ll POW(ll x, ll e) { ll v=1; for(; e; x=MUL(x,x), e>>=1) if (e&1) v = MUL(v,x); return v; }
ll DIV(ll x, ll y) { /*assert(y%MOD!=0);*/ return MUL(x, POW(y, MOD-2)); }
// ll comb(ll n, ll k) { ll v=1; for(ll i=1; i<=k; i++) v = DIV(MUL(v, n-i+1),i); return v; }
//

#define INTSPACE 12
char _buf[INTSPACE*1000000 + 3];

int loadint() {
    if (fgets(_buf, INTSPACE+3, stdin)==NULL) return 0;
    return atoi(_buf);
}

int loadvec(vector<int>& v, int N=-1) {
    if (N == 0) {
        v.clear();
        return 0;
    }
    if (N == -1) {
        N = loadint();
        if (N==0) return 0;
    }
    int bufsize = INTSPACE*N + 3;
    if (fgets(_buf, bufsize, stdin)==NULL) return 0;
    v.resize(N);

    int i=0;
    bool last = false;
    for (char *p=&_buf[0]; ;) {
        char *q = p;
        while (*q > ' ') ++q;
        if (*q == 0x0D || *q == 0x0A) last = true;
        *q = 0;
        v[i++] = atoi(p);
        if (last || i == N) break;
        p = q+1;
    }
    // assert(i <= N);
    return i;
}
void read_cr() {
    fgets(_buf, 256, stdin);
}

inline ll square(ll x) { return x * x; }


vll dp;
vll a, b;

ll f(int i, int x) {  // f(i,x) = a[i]x + b[i]
    return a[i]*(ll)x + b[i];
}

bool check(int i, int j, int k) {
    return (a[j] - a[i]) * (b[k] - b[j]) >= (b[j] - b[i]) * (a[k] - a[j]);
}

ll solve(int N, ll C, vi& h) {
    dp.resize(N);
    dp[0] = 0;

    a.resize(N);
    b.resize(N);
    a[0] = -2LL * h[0];
    b[0] = dp[0] + square(h[0]);

    deque<int> dq; // candidates

    // dp[i] = min{ dp[j] + (h_j - h_i)^2 + C) }
    //       = (h_i^2 + C) + min( dp[j] + h_j^2 - 2h_jh_i )
    //       = (h_i^2 + C) + min( ax + b )

    for (int i=1; i<N; ++i) {
        while (dq.size() >= 2 && check(dq[dq.size()-2], dq[dq.size()-1], i-1))
            dq.pop_back();
        dq.push_back(i-1);

        while (dq.size() >= 2 && f(dq[0], h[i]) >= f(dq[1], h[i])) dq.pop_front();

        ll minimum = f(dq[0], h[i]);
        dp[i] = (square(h[i]) + C) + minimum;

        a[i] = -2LL * h[i];
        b[i] = dp[i] + square(h[i]);
    }

    return dp[N-1];
}

int main() {
    int N; ll C; scanf("%d%lld", &N, &C); read_cr();
    vi h(N);
    loadvec(h,N);
    cout << solve(N,C,h) << endl;
    return 0;
}


Measured memory_bytes: 7552