use std::collections::VecDeque;
use std::env;
//use std::fmt::Debug;
use std::io;
use std::io::prelude::*;
//use std::time::{Duration, Instant};

//===================================================
// MACROs need to be defined above the use place ... ?
macro_rules! dprintln {
    ($($x:expr),*) => {{
        if $crate::is_debug_mode() {
            let f = || {println!( $($x),*)};
            f()
        }
    }}
}

/// Backward For-Loop Helper
///  from -> to (exclude `to`)
///
/// # Examples
/// see tests::macro_backward()
///
#[macro_export]
macro_rules! backward_ho {
    ($from:expr, $to:expr) => {{
        (($to + 1)..($from + 1)).rev()
    }};
}
//===================================================

fn main() {
    // Initialize
    set_debug_mode(false);
    for arg in env::args() {
        if arg == "--debug" {
            set_debug_mode(true);
        }
    }
    dprintln!("[DebugMode] {}", "On");

    // Execute
    dprintln!("=================");
    dprintln!("= READ INPUT     ");
    let stdin = io::stdin();
    let input = BufReadInput::new(stdin.lock());
    dprintln!("[Input] \n{:?}", input);
    dprintln!("=================");
    dprintln!("= INTERPRET INPUT");
    let q = input.into_quiz();
    dprintln!("[Quiz] \n{:?}", q);
    dprintln!("=================");
    dprintln!("= SOLVE QUIZE    ");
    let a = q.solve();
    dprintln!("[Answer] \n{:?}", a);
    dprintln!("=================");
    dprintln!("= PRINT ANSWER   ");
    a.print();
    dprintln!("=================");
}

#[derive(Debug)]
struct Quiz {
    n: usize,    // 1 <= n <= 100,000
    k: usize,    // 1 <= k <= 100,000
    w: Vec<u32>, // 1 <= w[i] <= 10,000, length=n
}

#[derive(Debug)]
struct Answer {
    min_p: u32,
}

trait IntoQuiz {
    fn into_quiz(self) -> Quiz;
}

impl<I: Input> IntoQuiz for I {
    fn into_quiz(mut self) -> Quiz {
        let n: usize = self.parse_next().unwrap();
        let k: usize = self.parse_next().unwrap();
        let w: Vec<u32> = self.parse_next_vec(n).unwrap();
        Quiz { n, k, w }
    }
}

impl Quiz {
    fn solve(self) -> Answer {
        let mut left_c_p = 1;
        let mut right_o_p = (10_000 * self.n as u32) / self.k as u32 + 1; // when max(w_i)=10,000

        while left_c_p < right_o_p {
            let mid_p = (right_o_p + left_c_p) / 2;
            dprintln!("search {} - {} - {}", left_c_p, mid_p, right_o_p);

            if Quiz::check(mid_p, self.k, &self.w) {
                // search left
                dprintln!(" {} is ok. next search left.", mid_p);
                right_o_p = mid_p;
            } else {
                // search right
                dprintln!(" {} is ng. next search right.", mid_p);
                left_c_p = mid_p + 1;
            }
        }

        Answer{ min_p : right_o_p }
    }

    fn check(p: u32, k: usize, w: &Vec<u32>) -> bool {
        // greedy 
        let mut r_p = p;
        let mut r_k = k;

        for &wi in w {
           if wi <= r_p {
               // Current truck can take w[i]
               r_p -= wi;
           } else {
               // Consider next truck
               if r_k > 1 && wi <= p {
                   // Next truck can take w[i]
                   r_k -= 1;
                   r_p = p - wi;
               } else {
                   // There is no truck can take wi.
                   return false;
               }
           }
        }
        true
    }
}

impl Answer {
    fn print(self) {
        println!("{}", self.min_p);
    }
}

// =====================================================
// =
// =====================================================

//==================================================
// Stdin Reader
#[derive(Debug)]
pub enum Token {
    Word(String),
    LineBreak,
}

impl Token {
    pub fn is_word(&self) -> bool {
        match *self {
            Token::Word(ref _x) => true,
            _ => false,
        }
    }
}

#[derive(Debug)]
pub struct BufReadInput<R: BufRead> {
    input: R,
    tokens: VecDeque<Token>,
}

pub trait Input {
    fn read_next_word(&mut self) -> Option<Token>;

    fn parse_next<T>(&mut self) -> Option<T>
    where
        T: std::str::FromStr,
    {
        if let Some(Token::Word(str)) = self.read_next_word() {
            match str.parse() {
                Ok(x) => Some(x),
                _ => None,
            }
        } else {
            None
        }
    }

    fn parse_next_vec<T>(&mut self, size: usize) -> Option<Vec<T>>
    where
        T: std::str::FromStr,
    {
        let mut v = Vec::new();

        for _i in 0..size {
            if let Some(t) = self.parse_next() {
                v.push(t);
            } else {
                return None;
            }
        }

        Some(v)
    }

    fn parse_next_vec2<T>(&mut self, size2: usize, size1: usize) -> Option<Vec<Vec<T>>>
    where
        T: std::str::FromStr,
    {
        let mut v = Vec::new();

        for _i in 0..size2 {
            if let Some(t) = self.parse_next_vec(size1) {
                v.push(t);
            } else {
                return None;
            }
        }

        Some(v)
    }

    fn parse_all_remaining_into_vec<T>(&mut self) -> Vec<T>
    where
        T: std::str::FromStr,
    {
        let mut v = Vec::new();

        loop {
            match self.parse_next() {
                Some(x) => v.push(x),
                None => return v,
            }
        }
    }
}
impl<R: BufRead> BufReadInput<R> {
    pub fn new(input: R) -> Self {
        let tokens = VecDeque::new();

        BufReadInput { input, tokens }
    }
}

impl<R: BufRead> Input for BufReadInput<R> {
    fn read_next_word(&mut self) -> Option<Token> {
        loop {
            match self.tokens.pop_front() {
                None => {
                    // Read Input
                    let mut line = String::new();
                    let n = self.input.read_line(&mut line).expect("Read Error.");
                    if n == 0 {
                        return None;
                    }
                    let mut line_tokens = tokenaize(line);
                    self.tokens.append(&mut line_tokens);
                }
                Some(Token::LineBreak) => (),
                x => return x,
            }
        }
    }

}

//TODO: Make CaseIterator
// ex) 
//  let mut input: Input ...
//  let mut iter: CaseIterator<Case=Command> = input.rest_into_cases(|i|   
//    let cmd:String = i.parse_next().expect("Parse error cmd");
//    let num:u32    = i.parse_next().expect("Parse error num");
//
//    Command::new(cmd, num)
//  );
//  let case1 = iter.next();
//  let case2 = iter.next();
//  ...


fn tokenaize(str: String) -> VecDeque<Token> {
    let mut v = VecDeque::new();

    for w in str.split_whitespace() {
        v.push_back(Token::Word(w.to_string()));
    }
    v.push_back(Token::LineBreak);
    v
}

//==================================================
// Utility Functions
pub fn concat_vec_to_string<T>(v: &Vec<T>) -> String
where
    T: std::fmt::Display,
{
    let mut string = String::with_capacity(v.len() * 2);

    if let Some((h, t)) = v.split_first() {
        string = h.to_string();

        for obj in t {
            string.push(' ');
            string.push_str(&obj.to_string());
        }
    }

    return string;
}

//==================================================
// Debug Switch
static mut S_DEBUG_MODE: bool = false;
fn is_debug_mode() -> bool {
    unsafe { S_DEBUG_MODE }
}

fn set_debug_mode(mode: bool) {
    unsafe {
        S_DEBUG_MODE = mode;
    }
}

//==================================================
// Usage
#[cfg(test)]
mod tests {
    use super::*;

    #[test]
    fn macro_backward() {
        let mut v = Vec::new();
        for i in backward_ho!(5, 1) {
            v.push(i);
        }
        assert_eq!(vec![5, 4, 3, 2], v);
    }
}



Measured memory_bytes: 5056