#include<bits/stdc++.h>
using namespace std;
using ll = long long;
int main(){
  ll n, k;
  cin >> n >> k;
  vector<vector<ll>> dp(k + 1, vector<ll>(2, -1000000000000));
  dp.at(0).at(0) = 0; dp.at(0).at(1) = 0;
  vector<ll> a(n, 0);
  for(int i = 0; i < n; i++){
    cin >> a.at(i);
  }
  for(int i = 0; i < n; i++){
    a.at(i) += 1000000000 + 1;
  }
  for(int i = 0; i < n; i++){
    for(int j = k; j >= 1; j--){
      if(dp.at(j - 1).at(1) != -1000000000000){
        dp.at(j).at(1) = max(dp.at(j).at(0), dp.at(j).at(1));
        dp.at(j).at(0) = dp.at(j - 1).at(1) + a.at(i);
      }
    }
  }
  if(max(dp.at(k).at(0), dp.at(k).at(1)) == -1e12){
    cout << "Impossible" << endl;
  }
  else{
    cout << (ll)max(dp.at(k).at(0), dp.at(k).at(1)) - (ll)k * (1000000000 + 1) << endl;
  }
}