#include<iostream>

int main() {
  int n, m;
  std::cin >> n >> m;
  int x;
  int stock = 0, nmin;
  for(int i = 0; i < n; ++i) {
    int a;
    std::cin >> a;
    int w = a / (m * (n - i));
    a %= m * (n - i);
    if(i == 0) {
      x = w;
      nmin = a;
    } else {
      if(w * m < nmin) {
        nmin -= w * m;
        x += w;
      } else if(w * m >= nmin) {
        x += nmin / m;
        break;
      }
      if(a < nmin) {
        while(nmin - a > stock) {
          if(nmin == 0) {
            goto end;
          } else {
            --nmin;
            stock += i;
          }
        }
        stock -= nmin - a;
        a += nmin - a;
      } else {
        stock += a - nmin;
      }
    }
  }
  x += nmin / m;
 end:
  std::cout << x << '\n';
}