#include <bits/stdc++.h>
using namespace std;
using ll = long long;
ll inf = (1LL<<35);

int main() {
    int n,k;
    cin >> n >> k;

    vector<vector<ll>>dp (n+1,vector<ll>(k+1,-inf));
    dp[0][0] = 0;

    for(int i=0;i<n;i++){
        ll x;
        cin >> x;

        for(int j=0;j<=k;j++){
            if(dp[i][j] == -inf) continue;

            dp[i+1][j] = max(dp[i+1][j], dp[i][j]);

            if(j != k){
                dp[min(i+2,n)][j+1] = max(dp[min(i+2,n)][j+1], dp[i][j] + x);
            }
        }
    }

    if(dp[n][k] == -inf) cout << "Impossible" << endl;
    else cout << dp[n][k] << endl;
}