#include <bits/stdc++.h>
using namespace std;
const int maxn = 200000, MAXN = 300000;
set<pair<int, int> > s[MAXN * 2];
int ans[MAXN], n;
void ok(int v, int t) {
  if (s[v].size() == 0) return;
  int u = s[v].begin()->first, ind = s[v].begin()->second;
  s[v].erase(s[v].begin());
  s[u].erase(pair<int, int>(v, ind));
  ans[ind] = t;
  ok(u, 1 - t);
}
int main() {
  ios_base::sync_with_stdio(false);
  cin >> n;
  for (int i = 0; i < n; i++) {
    int x, y;
    cin >> x >> y;
    y += maxn;
    s[x].insert(pair<int, int>(y, i));
    s[y].insert(pair<int, int>(x, i));
  }
  for (int i = 1; i <= 2 * maxn; i++)
    if (s[i].size() % 2 == 1) ok(i, 0);
  for (int i = 1; i <= 2 * maxn; i++)
    while (s[i].size() > 0) ok(i, 0);
  for (int i = 0; i < n; i++) {
    if (ans[i] == 0)
      cout << "b";
    else
      cout << "r";
  }
  cout << endl;
}
