content: import java.io.*;
  import java.math.*;
  import java.security.*;
  import java.text.*;
  import java.util.*;
  import java.util.concurrent.*;
  import java.util.regex.*;
  
  public class Solution {
  
    // Complete the workbook function below.
    static int workbook(int n, int k, int[] arr) {
      int counter = 0;
      int page = 1;
      for (int i = 0; i < arr.length; i++) {
        for (int j = 1; j <= arr[i]; j = j + k) {
          int current = k;
          if (j + k - 1 > arr[i]) {
            current = arr[i] % k;
          }
          if (j <= page && page < j + current) {
            counter++;
          }
          page++;
        }
      }
  
      return counter;
    }
  
    private static final Scanner scanner = new Scanner(System.in);
  
    public static void main(String[] args) throws IOException {
      BufferedWriter bufferedWriter = new BufferedWriter(new FileWriter(System.getenv("OUTPUT_PATH")));
  
      String[] nk = scanner.nextLine().split(" ");
  
      int n = Integer.parseInt(nk[0]);
  
      int k = Integer.parseInt(nk[1]);
  
      int[] arr = new int[n];
  
      String[] arrItems = scanner.nextLine().split(" ");
      scanner.skip("(\r\n|[\n\r\u2028\u2029\u0085])?");
  
      for (int i = 0; i < n; i++) {
        int arrItem = Integer.parseInt(arrItems[i]);
        arr[i] = arrItem;
      }
  
      int result = workbook(n, k, arr);
  
      bufferedWriter.write(String.valueOf(result));
      bufferedWriter.newLine();
  
      bufferedWriter.close();
  
      scanner.close();
    }
  }
  