#ifndef ONLINE_JUDGE
#define _GLIBCXX_DEBUG
#endif

#include <bits/stdc++.h>
using namespace std;
// #include <atcoder/all>
// using namespace atcoder;

using ll = long long;  // 2^63-1まで 負の値は可
// using ull = unsigned long long;  // 0 <= ull <=2^64-1の範囲 負の値は不可
using vl = vector<ll>;
// using vvl = vector<vl>;
// using P = pair<ll, ll>;
template <typename T>
using MNPQ = priority_queue<T, vector<T>, greater<T>>;
template <typename T>
using MXPQ = priority_queue<T, vector<T>, less<T>>;

#define overload(a, b, c, d, e, ...) e
#define FOR1(i, n) for (int i = 0; i < n; i++)
#define FOR2(i, s, n) for (int i = s; i < n; i++)
#define FOR3(i, s, n, a) for (int i = s; i < n; i += a)
#define rep(...) overload(__VA_ARGS__, FOR3, FOR2, FOR1)(__VA_ARGS__)
#define FOR1_R(i, n) for (int i = n - 1; i >= 0; i--)
#define FOR2_R(i, s, n) for (int i = s - 1; i >= n; i--)
#define FOR3_R(i, s, n, a) for (int i = s - 1; i >= n; i += a)
#define rrep(...) overload(__VA_ARGS__, FOR3_R, FOR2_R, FOR1_R)(__VA_ARGS__)

#define chmax(x, y) x = max(x, y)
#define chmin(x, y) x = min(x, y)
#define nall(a) a.begin(), a.end()
#define rall(a) a.rbegin(), a.rend()
#define YN(flg) cout << (flg ? "Yes" : "No") << "\n"
#define out_grid(x, y, h, w) !(0 <= x && x < h && 0 <= y && y < w)
#define debug(x) cerr << #x << " = " << x << endl;
const long long INF = 4e18;

template <typename T>
istream& operator>>(istream& is, vector<T>& a) {
    for (auto& x : a) is >> x;
    return is;
}

template <typename T>
ostream& operator<<(ostream& os, vector<T>& a) {
    for (int i = 0; i < (int)a.size(); i++) os << a[i] << " ";
    return os;
}

template <typename T1, typename T2>
ostream& operator<<(ostream& os, pair<T1, T2>& p) {
    os << "{" << p.first << "," << p.second << "}";
    return os;
}

template <typename K, typename V>
ostream& operator<<(ostream& os, map<K, V>& a) {
    for (auto& [k, v] : a) os << "{key:" << k << ", item:" << v << "} ";
    return os;
}

int main() {
    ios_base::sync_with_stdio(false);
    cin.tie(nullptr);

    ll n, k;
    cin >> n >> k;

    vector<vector<ll>> dp(n + 1, vector<ll>(k + 1, -INF));
    dp[0][0] = 0;
    rep(i, n) {
        ll a;
        cin >> a;
        dp[i + 1] = dp[i];
        chmax(dp[i + 1][1], a);
        rep(j, 1, k + 1) {
            if (i) {
                chmax(dp[i + 1][j], dp[i - 1][j - 1] + a);
            }
        }
    }
    ll ans = dp[n][k];
    if (ans < 0) {
        cout << "Impossible" << endl;
    } else {
        cout << ans << endl;
    }

    return 0;
}