#include <bits/stdc++.h>
using namespace std;
using ll = long long;
#define rep(i, a, b) for (ll i = (a); i < (ll)(b); i++)
#define all(x) x.begin(), x.end()

const ll INF = 1001001001001001001;

template <typename T>
inline bool chmax(T& a, const T& b) {
    return ((a < b) ? (a = b, true) : (false));
}

void solve() {
    int N, K;
    cin >> N >> K;
    vector<int> A(N);
    rep(i, 0, N) cin >> A[i];

    if (K * 2 - 1 > N) {
        cout << "Impossible\n";
        return;
    }

    vector dp(N + 1, vector(K + 1, vector<ll>(2, -INF)));
    dp[0][0][0] = 0;
    rep(i, 0, N) {
        rep(j, 0, K) {
            chmax(dp[i + 1][j][0], dp[i][j][0]);
            chmax(dp[i + 1][j][0], dp[i][j][1]);
            chmax(dp[i + 1][j + 1][1], dp[i][j][0] + A[i]);
        }
    }

    ll ans = -INF;
    chmax(ans, dp[N][K][0]);
    chmax(ans, dp[N][K][1]);
    cout << ans << '\n';
}

int main() {
    ios::sync_with_stdio(false);
    cin.tie(nullptr);
    int T = 1;
    // cin >> T;
    while (T--) {
        solve();
    }
}