#include <bits/stdc++.h>
using namespace std;
const int maxn = 1e5 + 5;
int n, m;
vector<int> ans;
bool p[maxn] = {false}, f[maxn] = {false};
char c[maxn];
int a[maxn];
bool flag = false;
set<int> s;
int main() {
  cin >> n >> m;
  for (int i = 0; i < m; i++) {
    cin >> c[i] >> a[i];
    if (c[i] == '+')
      p[a[i]] = true;
    else if (!p[a[i]]) {
      p[a[i]] = true;
      s.insert(a[i]);
    }
  }
  int cnt = s.size();
  if (cnt) flag = true;
  for (int i = 0; i < m; i++) {
    if (c[i] == '+') {
      cnt++;
      if (flag) f[a[i]] = true;
      flag = true;
      s.insert(a[i]);
    } else {
      cnt--;
      s.erase(a[i]);
      if (cnt)
        f[a[i]] = true;
      else if (i < m - 1 && (c[i + 1] != '+' || a[i + 1] != a[i]))
        f[a[i]] = true;
      else if (i < m - 1) {
        cnt++;
        s.insert(a[i]);
        i++;
      }
    }
  }
  for (int i = 1; i <= n; i++)
    if (!f[i]) ans.push_back(i);
  cout << ans.size() << endl;
  for (int i = 0; i < ans.size(); i++) cout << ans[i] << " ";
  cout << endl;
  return 0;
}
