#include <bits/stdc++.h>
using namespace std;
using ll = long long;

int main() {
    ios::sync_with_stdio(false);
    cin.tie(0);
    int n, k;
    cin >> n >> k;
    if(2 * k - 1 > n){
        cout << "Impossible\n";
        return 0;
    }
    constexpr ll INF = 1ll << 60;
    array<ll, 51> dp0, dp1;
    dp0.fill(-INF);
    dp1.fill(-INF);
    dp0[0] = 0;
    for(int i = 0, v; i < n; i++){
        cin >> v;
        array<ll, 51> ndp0 = dp0, ndp1;
        ndp1.fill(-INF);
        for(int j = k; j >= 0; j--){
            ndp0[j] = max(ndp0[j], dp1[j]);
            if(j) ndp1[j] = max(ndp1[j], dp0[j - 1] + v);
        }
        dp0 = ndp0;
        dp1 = ndp1;
    }
    ll ans = max(dp0[k], dp1[k]);
    if(ans < -(1ll << 40)) cout << "Impossible\n";
    else cout << ans << "\n";
}