use proconio::input;
fn main() {
    input! {
        n: usize,
        k: usize,
        a: [i64; n],
    }
    let mut dp = vec![vec![-1 << 60; 2]; k + 1];
    dp[0][0] = 0;
    // 0 unused 1 used
    for a in a {
        let mut ndp = vec![vec![-1 << 60; 2]; k + 1];
        for j in (0..=k).rev() {
            ndp[j][0] = dp[j][0].max(dp[j][1]);
            ndp[j][1] = dp[j][1];
            if j < k && dp[j][0] != - 1 << 60 {
                ndp[j + 1][1] = ndp[j + 1][1].max(dp[j][0] + a);
            }
        }
        dp = ndp;
    }
    let ans = dp[k][0].max(dp[k][1]);
    if ans == -1 << 60 {
        println!("Impossible");
        return;
    }
    println!("{ans}");
}