#include <bits/stdc++.h>
using namespace std;
inline void coutInt(int x) { cout << x << endl; }
inline void coutSpaceInt(int x) { cout << x << " "; }
inline void coutLong(long long x) { cout << x << endl; }
inline void coutSpaceLong(long long x) { cout << x << " "; }
const int N = 1e5 + 5;
int n, m, a[N], ans[N];
char c[N];
int main() {
  cin >> n >> m;
  for (int i = 0; i < m; i++) cin >> c[i] >> a[i];
  bool flag = false;
  int first = -1, sum = 0, cnt = 0;
  for (int i = 0; i < m; i++) {
    if (i == 0) {
      first = a[i];
      flag = true;
    }
    if (c[i] == '+') {
      if (a[i] != first && ans[first] == -1) flag = false;
      ans[a[i]] = 1;
      cnt++;
    } else {
      if (ans[a[i]] == 1) cnt--;
      if (a[i] != first && ans[a[i]] == 0) {
        first = a[i];
        flag = true;
      }
      if (a[i] == first && cnt) flag = false;
      ans[a[i]] = -1;
    }
  }
  if (flag) ans[first] = 0;
  for (int i = 1; i <= n; i++)
    if (ans[i] == 0) sum++;
  cout << sum << endl;
  for (int i = 1; i <= n; i++)
    if (ans[i] == 0) coutSpaceInt(i);
  cout << endl;
}
