#include <bits/stdc++.h>
#pragma GCC optimize("Ofast")
using namespace std;
const int N = 1e6 + 100;
pair<int, int> seg[4 * N];
int lazy[4 * N];
void shift(int nod) {
  lazy[nod * 2] += lazy[nod];
  lazy[nod * 2 + 1] += lazy[nod];
  seg[nod * 2].first += lazy[nod];
  seg[nod * 2 + 1].first += lazy[nod];
  seg[nod * 2].second += lazy[nod];
  seg[nod * 2 + 1].second += lazy[nod];
  lazy[nod] = 0;
}
void upd(int nod, int l, int r, int L, int R, int val) {
  if (l >= R || L >= r) {
    return;
  }
  if (l >= L && r <= R) {
    seg[nod].first += val;
    seg[nod].second += val;
    lazy[nod] += val;
    return;
  }
  shift(nod);
  int mid = (r + l) / 2;
  upd(nod * 2, l, mid, L, R, val);
  upd(nod * 2 + 1, mid, r, L, R, val);
  seg[nod].first = max(seg[nod * 2].first, seg[nod * 2 + 1].first);
  seg[nod].second = min(seg[nod * 2].second, seg[nod * 2 + 1].second);
}
int a[N];
int32_t main() {
  ios_base::sync_with_stdio(false);
  cin.tie(0);
  cout.tie(0);
  int n;
  cin >> n;
  int cnt = 1;
  int to = 0, tc = 0;
  for (int i = 0; i < n; i++) {
    char c;
    cin >> c;
    if (c == '(') {
      if (a[cnt] == 1) {
        if (to != tc || seg[1].second < 0) {
          cout << -1 << '\n';
        } else {
          cout << seg[1].first << '\n';
        }
        continue;
      }
      if (a[cnt] == 2) {
        upd(1, 1, N, cnt, N, +2);
        tc--;
      } else {
        upd(1, 1, N, cnt, N, 1);
      }
      a[cnt] = 1;
      to++;
    }
    if (c == ')') {
      if (a[cnt] == 2) {
        if (to != tc || seg[1].second < 0) {
          cout << -1 << '\n';
        } else {
          cout << seg[1].first << '\n';
        }
        continue;
      }
      if (a[cnt] == 1) {
        upd(1, 1, N, cnt, N, -2);
        to--;
      } else {
        upd(1, 1, N, cnt, N, -1);
      }
      tc++;
      a[cnt] = 2;
    }
    if (c == 'R') {
      cnt++;
    }
    if (c == 'L') {
      cnt--;
    }
    if (c >= 'a' && c <= 'z') {
      if (a[cnt] == 1) {
        a[cnt] = 0;
        upd(1, 1, N, cnt, N, -1);
        to--;
      }
      if (a[cnt] == 2) {
        a[cnt] = 0;
        upd(1, 1, N, cnt, N, +1);
        tc--;
      }
    }
    cnt = max(cnt, (int)1);
    if (to != tc || seg[1].second < 0) {
      cout << -1 << '\n';
    } else {
      cout << seg[1].first << '\n';
    }
  }
}
