#include <bits/stdc++.h>
using namespace std;
char ch[100001];
int per[100001];
bool is[100001];
bool vis[100001];
bool mem[100001];
bool have[100001];
vector<int> V;
int main() {
  int i, j;
  int a, b;
  int n, m;
  cin >> n >> m;
  for (i = 0; i < m; i++) {
    cin >> ch[i] >> per[i];
    have[per[i]] = true;
  }
  V.clear();
  memset(is, true, sizeof is);
  for (i = 0; i < m; i++) {
    if (ch[i] == '+') {
      if (!vis[per[i]] && i) is[per[i]] = false;
      if (V.size()) {
        is[per[i]] = false;
      } else {
        for (j = i - 1; j >= 0; j--) {
          if (per[i] != per[j]) is[per[j]] = false;
          if (mem[j]) break;
        }
        mem[i - 1] = true;
      }
      V.push_back(per[i]);
    } else {
      if (!vis[per[i]]) {
        for (j = i - 1; j >= 0; j--) {
          is[per[j]] = false;
          if (mem[j]) break;
        }
        mem[i - 1] = true;
        if (V.size()) is[per[i]] = false;
      } else if (V.size() == 1) {
        if (V[0] == per[i])
          V.clear();
        else {
          int num = per[i];
          V.erase(std::remove(V.begin(), V.end(), num), V.end());
          is[num] = false;
        }
      } else if (V.size()) {
        int num = per[i];
        V.erase(std::remove(V.begin(), V.end(), num), V.end());
        is[num] = false;
      }
    }
    if (!vis[per[i]]) vis[per[i]] = true;
  }
  vector<int> res;
  res.clear();
  for (i = 1; i <= n; i++) {
    if (!have[i]) {
      res.push_back(i);
    } else {
      if (is[i]) res.push_back(i);
    }
  }
  int sz = res.size();
  cout << sz << endl;
  for (i = 0; i < sz; i++) cout << res[i] << " ";
  return 0;
}
