#include <bits/stdc++.h>
using namespace std;
int main() {
  int n, m;
  cin >> n >> m;
  vector<pair<int, bool> > list(n);
  for (int i = 0; i < n; i++) cin >> list[i].first;
  int tmp;
  for (int i = 0; i < m; i++) {
    cin >> tmp;
    list[tmp - 1].second = 1;
  }
  vector<int> v1(n - m), v2(m);
  int c1 = 0, c2 = 0;
  for (int i = 0; i < n; i++) {
    if (list[i].second == 1)
      v2[c1++] = list[i].first;
    else
      v1[c2++] = list[i].first;
  }
  sort(v1.begin(), v1.end());
  sort(v2.begin(), v2.end());
  c1 = c2 = 0;
  long long cnt = 0;
  for (int i = 0; i < v1.size(); i++) cnt += v1[i];
  if (cnt < v2.back()) {
    cnt += v2.back();
    v2.back() = -1;
  }
  for (int i = 0; i < v2.size(); i++) {
    if (v2[i] != -1) cnt *= 2;
  }
  cout << cnt;
  return 0;
}
