#include <bits/stdc++.h>
using namespace std;
bool mustnot[100005];
char opr[100005];
int sum[100005];
int apr[100005];
int sat[100005];
int res[100005];
int a[100005];
int n, m, rc;
void work() {
  int i;
  memset(apr, -1, sizeof(apr));
  for (i = 1; i <= m; ++i)
    if (opr[i] == '+') {
      if (sat[a[i]] != i - 1) mustnot[a[i]] = 1;
      apr[a[i]] = 0;
      sat[a[i]] = i;
    } else {
      ++sum[sat[a[i]] + 1];
      --sum[i];
      apr[a[i]] = 1;
      sat[a[i]] = i;
    }
  for (i = 1; i <= n; ++i) {
    if (apr[i] == 1) {
      if (sat[i] != m) mustnot[i] = 1;
    }
    if (apr[i] == 0) ++sum[sat[i] + 1], --sum[m + 1];
  }
  for (i = 1; i <= m; ++i) sum[i] += sum[i - 1];
  for (i = 1; i <= m; ++i)
    if (sum[i]) mustnot[a[i]] = 1;
  for (i = 1; i <= n; ++i)
    if (!mustnot[i]) res[++rc] = i;
}
int main() {
  int i;
  scanf("%d%d\n", &n, &m);
  for (i = 1; i <= m; ++i) scanf("%c %d\n", &opr[i], &a[i]);
  work();
  printf("%d\n", rc);
  for (i = 1; i <= rc; ++i) printf("%d ", res[i]);
  printf("\n");
  return 0;
}
