#include <bits/stdc++.h>
using namespace std;
int A[100010];
pair<char, int> B[100010];
int kol = 0;
int main() {
  int n, m;
  cin >> n >> m;
  for (int i = 0; i < n; ++i) A[i] = 2;
  for (int i = 0; i < m; ++i) {
    cin >> B[i].first >> B[i].second;
    if (B[i].first == '+' && A[B[i].second - 1] == 2) {
      A[B[i].second - 1] = 1;
    }
    if (B[i].first == '-' && A[B[i].second - 1] == 2) {
      A[B[i].second - 1] = 0;
      ++kol;
    }
  }
  if (kol > 0)
    for (int i = 0; i < n; ++i)
      if (A[i] == 1) A[i] = 3;
  int flag = 0;
  for (int i = 0; i < m; ++i) {
    if (B[i].first == '+') {
      if (kol > 0) {
        A[B[i].second - 1] = 3;
      }
      if (kol == 0 && flag < 1000) {
        for (int j = 0; j < n; ++j) {
          if (j != B[i].second - 1 && A[j] != 2) A[j] = 3;
        }
        flag++;
      }
      ++kol;
    } else {
      if (kol == 1 && flag < 1000) {
        for (int j = 0; j < n; ++j) {
          if (j != B[i].second - 1 && A[j] != 2) A[j] = 3;
        }
        flag++;
      }
      if (kol > 1) A[B[i].second - 1] = 3;
      --kol;
    }
  }
  int answ = 0;
  for (int i = 0; i < n; ++i)
    if (A[i] == 0 || A[i] == 1 || A[i] == 2) ++answ;
  cout << answ << endl;
  for (int i = 0; i < n; ++i)
    if (A[i] == 0 || A[i] == 1 || A[i] == 2) cout << i + 1 << ' ';
}
