use proconio::input;
const INF: i64 = 1 << 60;

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

    let mut dp = vec![vec![-INF; 2]; k + 1];
    dp[0][0] = 0;
    for &a_i in &a {
        let mut next_dp = vec![vec![-INF; 2]; k + 1];
        for j in 0..=k {
            next_dp[j][0] = next_dp[j][0].max(dp[j][0]).max(dp[j][1]);
            if j < k && dp[j][0] != -INF {
                next_dp[j + 1][1] = next_dp[j + 1][1].max(dp[j][0] + a_i);
            }
        }

        dp = next_dp;
    }

    let ans = dp[k][0].max(dp[k][1]);
    if ans == -INF {
        println!("Impossible");
    } else {
        println!("{}", ans);
    }
}