#include <bits/stdc++.h>
using namespace std;
int main() {
  int n, m, li[200005] = {0}, flag = 0, last = -1, i, ans[200005], q[200005],
            cnt = 0, l = -1, sol = 0;
  cin >> n >> m;
  for (i = 0; i < n; ++i) ans[i] = 1;
  for (i = 0; i < m; ++i) {
    int var;
    char a[1];
    cin >> a[0] >> var;
    var--;
    q[i] = var;
    if (i == 1) flag = 1;
    if (a[0] == '+') {
      if (cnt) {
        li[var] = 1;
        ans[var] = 0;
      } else {
        li[var] = 1;
        if (l != -1 && l != var) {
          ans[var] = 0;
          ans[q[i - 1]] = 0;
          l = -1;
        }
      }
      cnt++;
    } else {
      if (!li[var]) {
        if (cnt) {
          ans[var] = 0;
          last = i;
        } else
          last = i - 1;
      } else {
        cnt--;
        if (cnt) ans[var] = 0;
      }
      if (!cnt) l = var;
    }
  }
  for (i = 0; i <= last; ++i) ans[q[i]] = 0;
  for (i = 0; i < n; ++i) {
    if (ans[i]) sol++;
  }
  printf("%d\n", sol);
  for (i = 0; i < n; ++i) {
    if (ans[i]) printf("%d ", i + 1);
  }
  return 0;
}
