#include <bits/stdc++.h>
using namespace std;
template <typename T>
inline int sz(const T& x) {
  return (int)x.size();
}
template <typename T>
inline void mn(T& x, const T& y) {
  if (y < x) x = y;
}
template <typename T>
inline void mx(T& x, const T& y) {
  if (x < y) x = y;
}
const int N = 100000;
pair<char, int> op[N];
int n, m;
vector<char> ops[N];
int main() {
  ios_base::sync_with_stdio(false);
  while (cin >> n >> m) {
    for (int i = 0; i < (n); ++i) {
      ops[i].resize(0);
    }
    for (int i = 0; i < (m); ++i) {
      cin >> op[i].first >> op[i].second;
      op[i].second--;
      ops[op[i].second].push_back(op[i].first);
    }
    bitset<100000> always;
    bitset<100000> curr;
    vector<int> ans;
    int count = 0;
    for (int i = 0; i < (n); ++i) {
      if (ops[i].empty()) {
        ans.push_back(i);
      } else {
        always[i] = 1;
        if (ops[i][0] == '-') {
          curr[i] = 1;
          count++;
        }
      }
    }
    if (count) always = curr;
    for (int i = 0; i < (m); ++i) {
      if (op[i].first == '-')
        curr[op[i].second] = 0, count--;
      else
        curr[op[i].second] = 1, count++;
      if (count) always &= curr;
    }
    for (int i = 0; i < (n); ++i)
      if (always[i]) ans.push_back(i);
    sort(std::begin(ans), std::end(ans));
    cout << ans.size() << endl;
    for (int x : ans) cout << x + 1 << ' ';
    cout << endl;
  }
  return 0;
}
