import java.util.Arrays;

class EnvelopeLinear {
  public static final long INF = Integer.MIN_VALUE;
  
  public long[] xs;
  public long[] intercepts, slopes;
  public int p;
  
  public EnvelopeLinear(int n)
  {
      xs = new long[n];
      intercepts = new long[n];
      slopes = new long[n];
      p = 0;
  }
  
  public void add(long slope, long intercept)
  {
      assert p == 0 || slopes[p-1] >= slope;
      while(p > 0){
          int i = p-1;
          if(intercept+xs[i]*slope <= intercepts[i]+xs[i]*slopes[i]){ // x=xs[i]
              p--;
              continue;
          }
          if(slope == slopes[i]){
              if(intercept >= intercepts[i]){
                  return;
              }else{
                  p--;
                  continue;
              }
          }
          long num = intercept-intercepts[i];
          long den = slopes[i]-slope;
          long nx = num < 0 ? num/den : (num+den-1)/den;
          xs[p] = nx;
          intercepts[p] = intercept;
          slopes[p] = slope;
          p++;
          return;
      }
      
      xs[p] = INF;
      intercepts[p] = intercept;
      slopes[p] = slope;
      p++;
  }
  
  public int argmin(int x)
  {
      if(p <= 0)return -1;
      int ind = Arrays.binarySearch(xs, 0, p, x);
      if(ind < 0)ind = -ind-2;
      return ind;
  }
  
  public long min(long x)
  {
      if(p <= 0)return Long.MIN_VALUE / 5;
      int ind = Arrays.binarySearch(xs, 0, p, x);
      if(ind < 0)ind = -ind-2;
      return slopes[ind]*x + intercepts[ind];
  }
}


public class Main {

  private static void solve() {
    int n = ni();
    long c = nl();
    long[] h = nal(n);

    long[] dp = new long[n];
    Arrays.fill(dp, Long.MAX_VALUE / 2);
    dp[0] = 0;
    EnvelopeLinear cht = new EnvelopeLinear(n);
    cht.add(-2 * h[0], h[0] * h[0]);
    for (int i = 1; i < n; i++) {
      long x = h[i];
      dp[i] = cht.min(x) + x * x + c;
    
      long a = -2 * h[i];
      long b = h[i] * h[i] + dp[i];
      cht.add(a, b);
    }

    System.out.println(dp[n - 1]);
  }

  public static void main(String[] args) {
    new Thread(null, new Runnable() {
      @Override
      public void run() {
        long start = System.currentTimeMillis();
        String debug = args.length > 0 ? args[0] : null;
        if (debug != null) {
          try {
            is = java.nio.file.Files.newInputStream(java.nio.file.Paths.get(debug));
          } catch (Exception e) {
            throw new RuntimeException(e);
          }
        }
        reader = new java.io.BufferedReader(new java.io.InputStreamReader(is), 32768);
        solve();
        out.flush();
        tr((System.currentTimeMillis() - start) + "ms");
      }
    }, "", 64000000).start();
  }

  private static java.io.InputStream is = System.in;
  private static java.io.PrintWriter out = new java.io.PrintWriter(System.out);
  private static java.util.StringTokenizer tokenizer = null;
  private static java.io.BufferedReader reader;

  public static String next() {
    while (tokenizer == null || !tokenizer.hasMoreTokens()) {
      try {
        tokenizer = new java.util.StringTokenizer(reader.readLine());
      } catch (Exception e) {
        throw new RuntimeException(e);
      }
    }
    return tokenizer.nextToken();
  }

  private static double nd() {
    return Double.parseDouble(next());
  }

  private static long nl() {
    return Long.parseLong(next());
  }

  private static int[] na(int n) {
    int[] a = new int[n];
    for (int i = 0; i < n; i++)
      a[i] = ni();
    return a;
  }

  private static char[] ns() {
    return next().toCharArray();
  }

  private static long[] nal(int n) {
    long[] a = new long[n];
    for (int i = 0; i < n; i++)
      a[i] = nl();
    return a;
  }

  private static int[][] ntable(int n, int m) {
    int[][] table = new int[n][m];
    for (int i = 0; i < n; i++) {
      for (int j = 0; j < m; j++) {
        table[i][j] = ni();
      }
    }
    return table;
  }

  private static int[][] nlist(int n, int m) {
    int[][] table = new int[m][n];
    for (int i = 0; i < n; i++) {
      for (int j = 0; j < m; j++) {
        table[j][i] = ni();
      }
    }
    return table;
  }

  private static int ni() {
    return Integer.parseInt(next());
  }

  private static void tr(Object... o) {
    if (is != System.in)
      System.out.println(java.util.Arrays.deepToString(o));
  }
}


Measured memory_bytes: 54584