#include <bits/stdc++.h>
#pragma GCC optimize("O3")
using namespace std;
int add(int a, int b) {
  long long x = a + b;
  if (x >= 1000000007) x -= 1000000007;
  if (x < 0) x += 1000000007;
  return x;
}
long long mul(long long a, long long b) { return (a * b) % 1000000007; }
long long pw(long long a, long long b) {
  long long ans = 1;
  while (b) {
    if (b & 1) ans = (ans * a) % 1000000007;
    a = (a * a) % 1000000007;
    b >>= 1;
  }
  return ans;
}
int bun[100005], type[100005], inside[100005], first[100005];
int main() {
  ios_base::sync_with_stdio(false);
  cin.tie(NULL);
  int n, k;
  cin >> n >> k;
  for (int i = 1; i <= n; ++i) bun[i] = 1;
  for (int i = 1; i <= k; ++i) {
    int aux;
    char c;
    cin >> c >> aux;
    if (c == '+')
      type[i] = +aux;
    else
      type[i] = -aux;
    if (!first[aux]) {
      if (c == '-') inside[aux] = 1;
      first[aux] = 1;
    }
  }
  int nr_inside = 0;
  for (int i = 1; i <= n; ++i) nr_inside += inside[i];
  for (int i = 1; i <= k; ++i) {
    if (type[i] < 0)
      nr_inside--;
    else
      nr_inside++;
    if (type[i] < 0) {
      if (nr_inside != 0)
        bun[-type[i]] = 0;
      else if (type[i + 1] != -type[i] && i != k)
        bun[-type[i]] = 0;
    } else {
      if (nr_inside != 1)
        bun[type[i]] = 0;
      else if (type[i - 1] != -type[i] && i != 1)
        bun[type[i]] = 0;
    }
  }
  int am = 0;
  for (int i = 1; i <= n; ++i) am += bun[i];
  cout << am << '\n';
  for (int i = 1; i <= n; ++i)
    if (bun[i]) cout << i << " ";
  return 0;
}
