#include <bits/stdc++.h>
using namespace std;
long long int id[100010];
int main() {
  long long int n, m, i, j, x, on = 0, leader = 0, event = 0, ex = 0;
  char ch;
  cin >> n >> m;
  memset(id, -1, sizeof(id));
  for (i = 1; i <= m; i++) {
    cin >> ch >> x;
    if (ch == '+') {
      id[x] = 1;
      if (leader == 0 && (event == 0 || ex == x)) {
        ex = leader;
        leader = x;
      }
      if (on == 0 && leader != x) ex = 0, leader = 0;
      on++;
    } else if (ch == '-') {
      if (id[x] == -1) {
        if (on == 0)
          ex = leader, leader = x;
        else if (i == m && on != 0)
          ex = leader, leader = 0;
        else if (on != 0 && leader != x)
          ex = leader, leader = 0;
      } else {
        if (leader == x && i != m) ex = leader, leader = 0;
        if (on != 1 && leader == x) ex = leader, leader = 0;
        on--;
      }
      id[x] = 0;
    }
    event++;
  }
  long long int cnk = 0;
  for (i = 1; i <= n; i++) {
    if (id[i] == -1) cnk++;
  }
  if (leader != 0) cnk++;
  cout << cnk << endl;
  for (i = 1; i <= n; i++) {
    if (i == leader || id[i] == -1) cout << i << " ";
  }
  return 0;
}
