use proconio::input;

fn main() {
    input! {
        n: usize,
        k: usize,
        a: [i64; n],
    }

    let mut dp = vec![[i64::MIN / 2; 2]; k + 1];
    let mut ndp = dp.clone();
    dp[0][0] = 0;
    for &ai in a.iter() {
        ndp.fill([i64::MIN / 2; 2]);
        for i in 0..=k {
            ndp[i][0] = dp[i][0].max(dp[i][1]);
        }

        for i in 0..k {
            ndp[i + 1][1] = ndp[i + 1][1].max(dp[i][0] + ai);
        }
        dp.clone_from_slice(&ndp);
    }
    let ans = dp[k][0].max(dp[k][1]);
    if ans < -1_000_000_000_000_000 {
        println!("Impossible");
    } else {
        println!("{ans}");
    }
}