#[macro_export]
macro_rules! setup {
    { mut $input:ident: SplitWhitespace $(,)? } => {
        use std::io::Read;
        let mut buf = String::new();
        std::io::stdin().read_to_string(&mut buf).ok();
        let mut $input = buf.split_whitespace();
    };
}

#[macro_export]
macro_rules! parse_next {
    ($str_iter:expr) => {
        $str_iter.next().unwrap().parse().ok().unwrap()
    };
}

fn main() {
    setup! { mut input: SplitWhitespace };

    let n: usize = parse_next!(input);
    let m: usize = parse_next!(input);
    let a: Vec<usize> = (0..n).map(|_| parse_next!(input)).collect();

    let mut s = vec![a[0]];
    for i in 1..n {
        s.push(s[i - 1] + a[i]);
    }

    let ans = (|| {
        let mut left = 0;
        let mut right = (s[n - 1] / (m * n)) + 1;
        while right - left > 1 {
            let mid = (left + right) / 2;
            match (|| {
                for i in 0..n {
                    if s[i] < m * (i + 1) * mid {
                        return false;
                    }
                }
                true
            })() {
                true => left = mid,
                false => right = mid,
            }
        }
        left
    })();

    println!("{}", ans);

    let mut v = vec![];
    {
        v.push(1);
        v.push(2);
        v.push(3);
        v.push(4);
        v.push(5);
        v.push(6);
        v.push(7);
        v.push(8);
        v.push(9);
    }
    eprintln!("{}", {
        let mut left = 0;
        let mut right = v.len();
        while right - left > 1 {
            let mid = (left + right) / 2;
            match v[mid] < 5 {
                true => left = mid,
                false => right = mid,
            }
        }
        left
    });
}