#include <bits/stdc++.h>
using namespace std;
int main() {
  ios_base::sync_with_stdio(false);
  long long n, m, i, ans = 0, z, j;
  pair<long long, long long> a[105];
  vector<pair<long long, long long> > q;
  cin >> n >> m;
  for (i = 1; i <= n; i++) a[i].second = 0;
  for (i = 1; i <= n; i++) cin >> a[i].first;
  for (j = 1; j <= m; j++) {
    cin >> z;
    a[z].second = 1;
  }
  for (i = 1; i <= n; i++) q.push_back(a[i]);
  sort(q.begin(), q.end());
  for (i = 0; i < n; i++)
    if (q[i].second == 0) ans += q[i].first;
  for (i = n - 1; i >= 0; i--)
    if (q[i].second == 1) ans = ans + max(ans, q[i].first);
  cout << ans << endl;
  return 0;
}
