#include <bits/stdc++.h>
using namespace std;
int main() {
  ios::sync_with_stdio(false);
  int t = 0, i = 0, j = 0, n = 0, m = 0, k = 0, num = 0, temp = 0, ans;
  cin >> n >> m;
  ans = n;
  bool pos[100002];
  for (i = 0; i <= n; ++i) pos[i] = true;
  string str;
  str.resize(100002);
  int arr[100002];
  bool vis[100002] = {false};
  set<int> s1, s2;
  char ch;
  set<int>::iterator it;
  for (i = 0; i < m; ++i) {
    cin >> str[i] >> arr[i];
    if (vis[arr[i]] == false) {
      if (str[i] == '+') {
        s2.insert(arr[i]);
      } else {
        s1.insert(arr[i]);
      }
    }
    vis[arr[i]] = true;
  }
  if (s1.size() > 0) {
    for (it = s2.begin(); it != s2.end(); ++it) {
      pos[(*it)] = false;
    }
    s2.clear();
  }
  for (i = 0; i < m; ++i) {
    if (str[i] == '+') {
      if (s1.size() > 0) {
        pos[arr[i]] = false;
      }
      s1.insert(arr[i]);
      s2.erase(arr[i]);
    } else {
      s1.erase(arr[i]);
      if (pos[arr[i]]) s2.insert(arr[i]);
      if (s1.size() > 0) pos[arr[i]] = false;
    }
    if (s1.size() > 0) {
      for (it = s2.begin(); it != s2.end(); ++it) {
        pos[(*it)] = false;
      }
      s2.clear();
    }
  }
  for (i = 1; i <= n; ++i) {
    if (pos[i] == true) num++;
  }
  cout << num << endl;
  for (i = 1; i <= n; ++i) {
    if (pos[i]) cout << i << " ";
  }
  return 0;
}
