#include <bits/stdc++.h>
using namespace std;
int n;
pair<int, int> p[200010];
set<int> mf[200010], ms[200010];
map<pair<int, int>, int> color;
set<int>::iterator it;
void read() {
  for (int i = 0; i < n; i++) {
    scanf("%d%d", &p[i].first, &p[i].second);
    mf[p[i].first].insert(p[i].second);
    ms[p[i].second].insert(p[i].first);
  }
}
void dfs(int p, int second, int c) {
  if (second == 1) {
    if (mf[p].empty()) return;
    int y = *mf[p].begin();
    color[make_pair(p, y)] = c;
    mf[p].erase(y);
    ms[y].erase(p);
    dfs(y, 1 - second, 3 - c);
  } else {
    if (ms[p].empty()) return;
    int x = *ms[p].begin();
    color[make_pair(x, p)] = c;
    ms[p].erase(x);
    mf[x].erase(p);
    dfs(x, 1 - second, 3 - c);
  }
}
void work() {
  for (int i = 0; i < n; i++) {
    if (!color[p[i]]) {
      color[p[i]] = 1;
      mf[p[i].first].erase(p[i].second);
      ms[p[i].second].erase(p[i].first);
      dfs(p[i].first, 1, 2);
      dfs(p[i].second, 0, 2);
    }
  }
  for (int i = 0; i < n; i++) {
    if (color[p[i]] == 1)
      printf("b");
    else
      printf("r");
  }
  puts("");
}
int main() {
  while (~scanf("%d", &n)) {
    read();
    work();
  }
  return 0;
}
