#include <bits/stdc++.h>
using namespace std;
bool appear[100010];
bool on[100010];
int _time[100010];
bool bad[100010];
struct event {
  int z, id;
};
vector<event> in;
vector<event> comp;
int main() {
  int n, m;
  scanf("%d%d\n", &n, &m);
  char c;
  int d;
  vector<int> prv;
  for (int i = 0; i < m; i++) {
    scanf("%c %d\n", &c, &d);
    d--;
    appear[d] = true;
    if (c == '-') {
      if (!on[d]) prv.push_back(d);
      on[d] = false;
    }
    if (c == '+') {
      on[d] = true;
      _time[d] = i;
    }
    in.push_back({c == '+' ? 1 : -1, d});
  }
  for (auto it = prv.rbegin(); it != prv.rend(); it++) {
    comp.push_back({1, *it});
  }
  for (auto pp : in) {
    comp.push_back(pp);
  }
  vector<pair<int, int>> vp;
  for (int i = 0; i < n; i++) {
    if (on[i]) {
      vp.push_back({-_time[i], i});
    }
  }
  sort(begin(vp), end(vp));
  for (int i = 0; i < vp.size(); i++) {
    comp.push_back({-1, vp[i].second});
  }
  int cnt = 0;
  vector<int> ap;
  int leader = -1;
  for (auto pp : comp) {
    if (pp.z == 1) {
      if (cnt != 0) bad[pp.id] = true;
      cnt++;
    } else {
      cnt--;
      if (cnt != 0) bad[pp.id] = true;
      if (cnt == 0) {
        if (leader >= 0 && pp.id != leader) {
          leader = -2;
        } else if (leader == -1) {
          leader = pp.id;
        }
      }
    }
  }
  int ans = 0;
  for (int i = 0; i < n; i++) {
    if (!appear[i])
      ans++;
    else if (!bad[i] && i == leader)
      ans++;
  }
  cout << ans << endl;
  for (int i = 0; i < n; i++) {
    if (!appear[i] || (!bad[i] && i == leader)) printf("%d ", i + 1);
  }
  puts("");
}
