import java.io.IOException;
import java.io.InputStream;
import java.io.PrintWriter;
import java.util.Arrays;
import java.util.InputMismatchException;
import java.util.LinkedList;
import java.util.PriorityQueue;
import java.util.TreeSet;

 
public class Main {
  public static void main(String[] args) {
    InputReader sc = new InputReader(System.in);
 
    int n = sc.nextInt();
    int k = sc.nextInt();
    int[] weights = new int[n];
    int max = 0;
    for(int i = 0; i < n; i++){
      weights[i] = sc.nextInt();
      if(max < weights[i]){
        max = weights[i];
      }
    }

    int jogen = 1000000000;
    int kagen = max;
    int center;
    int count;
    int nowsum;
    while(jogen - kagen  >= 2){
      center = (jogen + kagen) / 2;
      count = 1;
      nowsum = 0;
      for(int i = 0; i < n; i++){
        if(nowsum + weights[i] > center){
          count++;
          nowsum = weights[i];
        }else{
          nowsum += weights[i];
        }
      }
      if(nowsum > center){count++;}
      if(count > k){
        kagen = center;
      }else{
        jogen = center;
      }
    }

    count = 1;
    nowsum = 0;
    for(int i = 0; i < n; i++){
      if(nowsum + weights[i] > kagen){
        count++;
        nowsum = weights[i];
      }else{
        nowsum += weights[i];
      }
    }
    if(nowsum > kagen){count++;}
    if(count > k){
      System.out.println(jogen);
    }else{
      System.out.println(kagen);
    }
  }
 
  
// LinkedList<Integer>[] setsu = new LinkedList[n];
// for(int i = 0; i < n; i++){
//   setsu[i] = new LinkedList<Integer>();
// } 

 //ここからテンプレ
  static class InputReader {
      private InputStream stream;
      private byte[] buf = new byte[1024];
      private int curChar;
      private int numChars;
      private SpaceCharFilter filter;

      public InputReader(InputStream stream) {
          this.stream = stream;
      }
 
      public int next() {
          if (numChars == -1)
              throw new InputMismatchException();
          if (curChar >= numChars) {
              curChar = 0;
              try {
                  numChars = stream.read(buf);
              } catch (IOException e) {
                  throw new InputMismatchException();
              }
              if (numChars <= 0)
                  return -1;
          }
          return buf[curChar++];
      }
 
      public String nextStr() {
        int c = next();
        while(isSpaceChar(c)){c = next();}
        StringBuffer str = new StringBuffer();
        do{
          str.append((char)c);
          c = next();
        }while(!isSpaceChar(c));
        return str.toString();
      }

      public int nextInt() {
          int c = next();
          while (isSpaceChar(c))
              c = next();
          int sgn = 1;
          if (c == '-') {
              sgn = -1;
              c = next();
          }
          int res = 0;
          do {
              if (c < '0' || c > '9')
                  throw new InputMismatchException();
              res *= 10;
              res += c - '0';
              c = next();
          } while (!isSpaceChar(c));
          return res * sgn;
      }
 
      public boolean isSpaceChar(int c) {
          if (filter != null)
              return filter.isSpaceChar(c);
          return c == ' ' || c == '\n' || c == '\r' || c == '\t' || c == -1;
      }
 
      public interface SpaceCharFilter {
          public boolean isSpaceChar(int ch);
      }
  }
}

Measured memory_bytes: 21140