import std.conv, std.stdio, std.string;
import std.algorithm, std.array, std.bigint, std.container, std.math, std.range, std.regex, std.typecons;
import core.bitop, core.thread;

class EOFException : Throwable { this() { super("EOF"); } }
string[] tokens;
string readToken() { for (; tokens.empty; ) { if (stdin.eof) throw new EOFException; tokens = readln.split; } auto token = tokens[0]; tokens.popFront; return token; }
int readInt() { return readToken().to!int; }
long readLong() { return readToken().to!long; }
real readReal() { return readToken().to!real; }

void chmin(T)(ref T t, in T f) { if (t > f) t = f; }
void chmax(T)(ref T t, in T f) { if (t < f) t = f; }

int binarySearch(T)(in T[] as, in bool delegate(T) test) { int low = -1, upp = cast(int)(as.length); for (; low + 1 < upp; ) { int mid = (low + upp) >> 1; (test(as[mid]) ? low : upp) = mid; } return upp; }
int lowerBound(T)(in T[] as, in T val) { return as.binarySearch((T a) => (a < val)); }
int upperBound(T)(in T[] as, in T val) { return as.binarySearch((T a) => (a <= val)); }


int N;
long C;
long[] H;

void main() {
  try {
    for (; ; ) {
      N = readInt();
      C = readLong();
      H = new long[N];
      foreach (i; 0 .. N) {
        H[i] = readLong();
      }
      Tuple!(long, long)[] q;
      auto dp = new long[N];
      foreach (i; 0 .. N) {
        if (i == 0) {
          dp[i] = 0;
        } else {
          debug {
            writefln("i = %s, q = %s", i, q);
          }
          for (; q.length >= 2; q.popFront) {
            if (q[0][0] + q[0][1] * H[i] < q[1][0] + q[1][1] * H[i]) {
              break;
            }
          }
          debug {
            writefln("i = %s, q = %s", i, q);
          }
          dp[i] = q[0][0] + q[0][1] * H[i];
          dp[i] += H[i] * H[i] + C;
        }
        const a = tuple(dp[i] + H[i] * H[i], -2 * H[i]);
        for (; q.length >= 2; q.popBack) {
          /*
            -(q[$ - 2][0] - q[$ - 1][0]) / (q[$ - 2][1] - q[$ - 1][1]) < -(q[$ - 1][0] - a[0]) / (q[$ - 1][1] - a[1])
          */
          if (-(q[$ - 2][0] - q[$ - 1][0]) * (q[$ - 1][1] - a[1]) < -(q[$ - 1][0] - a[0]) * (q[$ - 2][1] - q[$ - 1][1])) {
            break;
          }
        }
        q ~= a;
      }
      debug {
        writefln("dp = %s", dp);
      }
      writeln(dp[N - 1]);
    }
  } catch (EOFException e) {
  }
}
