#include <bits/stdc++.h>
using namespace std;
int arr[100005];
int main() {
  memset(arr, 0, sizeof(arr));
  int first = -1;
  bool first_flag = false;
  int n, m, temp, sum = 0, countOn = 0;
  char ch;
  scanf("%d %d%*c", &n, &m);
  for (int i = 0; i < m; i++) {
    scanf("%c %d%*c", &ch, &temp);
    if (i == 0) {
      first = temp;
      first_flag = true;
    }
    if (ch == '+') {
      if (temp != first && arr[first] == -1) first_flag = false;
      arr[temp] = 1;
      countOn++;
    } else {
      if (arr[temp] == 1) countOn--;
      if (temp != first && arr[temp] == 0) {
        first = temp;
        first_flag = true;
      }
      if (temp == first && countOn > 0) first_flag = false;
      arr[temp] = -1;
    }
  }
  if (first_flag) arr[first] = 0;
  for (int i = 1; i <= n; i++) {
    if (arr[i] == 0) sum++;
  }
  cout << sum << endl;
  for (int i = 1; i <= n; i++) {
    if (arr[i] == 0) cout << i << " ";
  }
  return 0;
}
