#include <bits/stdc++.h>
using namespace std;
int main() {
  int q, w, e, r, t = 0, y = 0;
  bool s[100001], d[100001];
  char a[2];
  cin >> q >> w;
  for (e = 1; e <= q; e++) {
    s[e] = 1;
    d[e] = 0;
  }
  bool c = 1, v;
  for (e = 0; e < w; e++) {
    scanf("%s%d", a, &r);
    if (a[0] == '+') {
      if ((t == 0) || (t == r))
        t = r;
      else
        s[r] = 0;
      d[r] = 1;
      if ((t != r) && (d[t] == 0)) s[t] = 0;
      y++;
    } else {
      if (t == 0) t = r;
      if ((t != r) && (d[r] == 0)) {
        s[t] = 0;
        t = r;
      }
      if (d[r]) {
        d[r] = 0;
        y--;
      }
      if (y > 0) s[r] = 0;
    }
  }
  e = 0;
  for (w = 1; w <= q; w++)
    if (s[w]) e++;
  cout << e << "\n";
  for (w = 1; w <= q; w++)
    if (s[w]) printf("%d ", w);
  return 0;
}
