#include <cstdio>
#include <cstring>
#include <cstdint>
#include <cstdlib>
#include <cstddef>
#include <cinttypes>

#include <type_traits>
#include <limits>

/* FastIO by rsk0315 (last update: 2018/02/21 00:36) */

namespace FastIn {
  static constexpr size_t BUF_SIZE=1<<17, INT_LEN=24, FLT_LEN=400;
  static char buf[BUF_SIZE|1]={}, *pos=buf, *endbuf=nullptr;
  FILE *fin;

  inline bool rebuffer() {
    // returns true <=> there is at least one unread character
    size_t rest=endbuf-pos;
    if (buf+rest > pos) {
      // buf[:pos] and buf[-pos:] are overlapping, which std::memcpy()
      // causes undefined behavior.
      return true;
    }

    std::memcpy(buf, pos, rest); 
    pos = buf;
    size_t len=std::fread(pos+rest, 1, BUF_SIZE-rest, fin);
    *(endbuf = buf + (rest+len)) = 0;

    return *pos;
  }

  inline bool scan(char &in) {
    if ((in = *pos)) {
      ++pos;
      return true;
    }

    return rebuffer() && (in = *pos++);
  }

  inline bool scan(char *in) {
    if ((*in = *pos) == 0) {
      if (rebuffer() && (*in = *pos) == 0) {
        return false;
      }
    }
    ++in;
    while (true) {
      if ((*in = *pos++) == 0) {
        if (rebuffer() && (*in = *pos++) == 0) {
          return true;
        }
      }
      ++in;
    }
  }

  inline bool scan(double &in) {
    if (pos + FLT_LEN >= endbuf && !rebuffer()) {
      in = 0.0;
      return false;
    }

    char *tmp;
    in = std::strtod(pos, &tmp);
    pos = tmp;
    return true;
  }

  template <class Int>
  inline bool scan(Int &in) {
    in = 0;

    // assume that no redundant whitespace appears
    if (pos + INT_LEN >= endbuf && !rebuffer()) {
      return false;
    }

    if (std::is_signed<Int>::value) {
      if (*pos == '-') {
        in = ~*++pos+'1';
        while (*++pos >= '0') {
          in = in*10 + ~*pos+'1';
        }
        ++pos;
        return true;
      }
    }

    // assume that numbers are separated by the character whose value is
    // less than '0' (e.g. whitespaces, newlines)
    do {
      in = in*10 + *pos-'0';
    } while (*++pos >= '0');
    ++pos;
    return true;
  }

  inline bool eat() {
    if (*pos > ' ') {
      return true;
    }

    do {
      if (*pos == 0 && !rebuffer()) {
        return false;
      }
    } while (*++pos <= ' ');

    return true;
  }

  inline bool eat(char ch) {
    if (*pos == ch) {
      return true;
    }

    do {
      if (*pos == 0 && !rebuffer()) {
        return false;
      }
    } while (*++pos != ch);

    return true;
  }

  class Scanner {
    bool rebuffer() {
      return FastIn::rebuffer();
    }

  public:
    Scanner(FILE *fin=stdin) {
      FastIn::fin = fin;
      endbuf = pos + std::fread(buf, 1, BUF_SIZE, fin);
    }

    template <class T>
    inline bool scan(T &in) {
      return FastIn::scan(in);
    }

    template <class First, class... Rest>
    inline bool scan(First &in, Rest &...ins) {
      return scan(in) && scan(ins...);
    }
  };
}

// end of Fast IO

#include <cstdio>
#include <cstdint>
#include <algorithm>
#include <string>
#include <utility>
#include <vector>
#include <map>
#include <type_traits>
#include <limits>
#include <tuple>

template <class Tp>
class lines {
  // based on Li Chao tree
  // std::map<Tp, size_t> enc;
  std::vector<Tp> dec;
  std::vector<std::pair<Tp, Tp>> c;
  size_t m = 1;
  Tp inf = std::numeric_limits<Tp>::max() / 8;

private:
  void init_resize(size_t n) {
    while (m < n+n) m <<= 1;
    c.assign(m, {0, inf});
  }

  void inspect() const {
    for (size_t i = 1; i < m; ++i) {
      std::string s = (c[i].first < inf? std::to_string(c[i].first) : "inf");
      std::string t = (c[i].second < inf? std::to_string(c[i].second) : "inf");
      fprintf(stderr, "(%s, %s)%c", s.c_str(), t.c_str(), (i&(i+1))? ' ':'\n');
    }
  }

public:
  template <class ForwardIt>
  lines(ForwardIt first, ForwardIt last): dec(first, last) {
    static_assert(std::is_same<typename ForwardIt::value_type, Tp>::value, "Type mismatch");
    std::sort(dec.begin(), dec.end());
    size_t n = dec.size();
    init_resize(n);
    // while (dec.size() < m/2) dec.push_back(dec.back()+1);
    dec.resize(m/2, dec.back()+1);
    // for (size_t i = 0; i < m/2; ++i) enc.emplace(dec[i], i);
  }

  void append(Tp a, Tp b) {
    size_t l = 0;
    size_t j = 1;
    size_t h = 1;
    size_t w = m/2;
    while (w > 0 && l+w-1 < dec.size()) {
      Tp xl = dec[l];
      Tp xm = dec[l+w/2];
      Tp xr = dec[l+w-1];

      Tp a0, b0;
      std::tie(a0, b0) = c[j];

      Tp yl0 = a0*xl + b0;
      Tp yr0 = a0*xr + b0;

      Tp yl = a*xl + b;
      Tp yr = a*xr + b;

      if (yl0 <= yl && yr0 <= yr) break;
      if (yl0 >= yl && yr0 >= yr) {
        c[j] = {a, b};
        break;
      }

      h <<= 1;
      w >>= 1;
      Tp ym0 = a0*xm + b0;
      Tp ym = a*xm + b;

      if (ym0 >= ym) {
        c[j] = {a, b};
        a = a0;
        b = b0;
        j <<= 1;
        if (yr0 < yr) {
          j |= 1;
          l += w;
        }
      } else {
        j <<= 1;
        if (yr0 >= yr) {
          j |= 1;
          l += w;
        }
      }
    }
  }

  Tp min_at(size_t i, Tp x) const {
    i += m/2;
    Tp y = inf;
    while (i > 0) {
      Tp a, b;
      std::tie(a, b) = c[i];
      y = std::min(y, a*x+b);
      i >>= 1;
    }
    return y;
  }
};

FastIn::Scanner cin;

int main() {
  size_t N;
  intmax_t C;
  cin.scan(N, C);

  std::vector<intmax_t> h(N);
  for (auto& hi: h) cin.scan(hi);

  lines<intmax_t> cht(h.begin(), h.end());

  std::vector<intmax_t> dp(N);
  for (size_t i = 0; i+1 < N; ++i) {
    cht.append(-2*h[i], h[i]*h[i]+dp[i]);
    dp[i+1] = cht.min_at(i+1, h[i+1]) + h[i+1]*h[i+1] + C;
  }

  printf("%jd\n", dp[N-1]);
}

Measured memory_bytes: 14720