#include <bits/stdc++.h>
using namespace std;
int n, k, m, kil, aa[100001], ab[100001], first;
char ch;
string s;
long long ans;
int main() {
  cin >> n >> m;
  for (int i = 1; i <= m; i++) {
    cin >> ch >> k;
    if (ch == '+') {
      if (kil > 0)
        aa[k] = 1;
      else {
        if (first != k) {
          aa[first] = 1;
          if (first > 0) aa[k] = 1;
        }
        first = k;
      }
      kil++;
      ab[k] = 1;
    }
    if (ch == '-') {
      if (ab[k] > 0) {
        if (kil > 1) aa[k] = 1;
      } else if (kil > 0)
        aa[k] = 1;
      if (ab[k] == 0) {
        aa[first] = 1;
        first = k;
      } else
        kil--;
      ab[k] = 0;
    }
  }
  for (int i = 1; i <= n; i++)
    if (!aa[i]) ans++;
  cout << ans << endl;
  for (int i = 1; i <= n; i++)
    if (!aa[i]) cout << i << " ";
}
