# Original solution
class Lichaotree:
    #区間は1-indexed
    #min
    def __init__(self, X):
        self.N = len(X)
        self.N0 = 2**(self.N-1).bit_length()
        self.comp = {v : k for k, v in enumerate(X)}
        self.inf = 10**19
        self.X = X + [self.inf]*(self.N0 - self.N)
        self.data = [None]*(2*self.N0)
        self.size = [0]*self.N0 + [1]*self.N0
        for i in range(self.N0-1, 0, -1):
            self.size[i] = 2*self.size[2*i]
        
    def f(self, line, x):
        return line[0]*x + line[1]

    def _update(self, k, line):
        
        if self.data[k] is None:
            self.data[k] = line
            return
        
        l = k - (1 << (k.bit_length() - 1))
        r = l + self.size[k]

        
        while True:
            if self.data[k] is None:
                self.data[k] = line
                return
            
            m = (l+r)//2
            lx = self.X[l]
            mx = self.X[m]
            rx = self.X[r-1]
            gl = (self.f(self.data[k], lx) > self.f(line, lx))
            gm = (self.f(self.data[k], mx) > self.f(line, mx))
            gr = (self.f(self.data[k], rx) > self.f(line, rx))
            if gl and gr:
                self.data[k] = line
                return
            
            if not gl and not gr:
                return
            
            if gm:
                self.data[k], line = line, self.data[k]
                gl = not gl
                
            if gl:
                r = m
                k = 2*k
            else:
                l = m
                k = 2*k+1
    
    def query(self, x):
        k = self.comp[x] + self.N0
        s = self.inf
        while k > 0:
            if self.data[k]:
                s = min(s, self.f(self.data[k], x))
            k = k >> 1
        return s
            
    def addline(self, line):
        self._update(1, line)

N, C = list(map(int, input().split()))
H = list(map(int, input().split()))

T = Lichaotree(H)
dp = [10**19]*N
dp[0] = 0
T.addline((-2*H[0], H[0]**2))
for i in range(1,N):
    mi = T.query(H[i])
    dp[i] = mi + C + H[i]**2
    T.addline((-2*H[i], H[i]**2+dp[i]))
print((dp[-1]))


# Optimized solution
class Lichaotree:
    #区間は1-indexed
    #min
    def __init__(self, X):
        self.N = len(X)
        self.N0 = 2**(self.N-1).bit_length()
        self.comp = {v : k for k, v in enumerate(X)}
        self.inf = 10**12
        self.X = X + [self.inf]*(self.N0 - self.N)
        self.data = [None]*(2*self.N0)
        self.size = [0]*self.N0 + [1]*self.N0
        for i in range(self.N0-1, 0, -1):
            self.size[i] = 2*self.size[2*i]
        self.start = [0]*(2*self.N0)
        for i in range(1, 2*self.N0):
            if i == i&(-i):
                continue
            self.start[i] = self.start[i-1] + self.size[i]
        
    def f(self, line, x):
        return line[0]*x + line[1]

    def _update(self, k, line):
        
        if self.data[k] is None:
            self.data[k] = line
            return
        
        l = self.start[k]
        r = l + self.size[k]        
        
        while True:
            if self.data[k] is None:
                self.data[k] = line
                return
            
            m = (l+r)//2
            lx = self.X[l]
            mx = self.X[m]
            rx = self.X[r-1]
            gl = (self.f(self.data[k], lx) > self.f(line, lx))
            gm = (self.f(self.data[k], mx) > self.f(line, mx))
            gr = (self.f(self.data[k], rx) > self.f(line, rx))
            if gl and gr:
                self.data[k] = line
                return
            
            if not gl and not gr:
                return
            
            if gm:
                self.data[k], line = line, self.data[k]
                gl = not gl
                
            if gl:
                r = m
                k = 2*k
            else:
                l = m
                k = 2*k+1
    
    def query(self, x):
        k = self.comp[x] + self.N0
        s = self.inf
        while k > 0:
            if self.data[k]:
                s = min(s, self.f(self.data[k], x))
            k = k >> 1
        return s
            
    def addline(self, line):
        self._update(1, line)
    
    def addlineseg(self, l, r, line):
        #区間[l, r)にlineを追加,l, rはXの元
        
        L = l+self.N0
        R = r+self.N0
        while L < R:
            if R & 1:
                R -= 1
                self._update(R, line)
            if L & 1:
                self._update(L, line)
                L += 1
            L >>= 1
            R >>= 1

N, C = list(map(int, input().split()))
H = list(map(int, input().split()))

T = Lichaotree(H)
dp = [10**19]*N
dp[0] = 0
T.addline((-2*H[0], H[0]**2))
for i in range(1,N):
    mi = T.query(H[i])
    dp[i] = mi + C + H[i]**2
    T.addline((-2*H[i], H[i]**2+dp[i]))
print((dp[-1]))