#include <bits/stdc++.h>
using namespace std;
const int S = 2e5 + 1;
int k[2][S], c[S];
vector<int> g[S];
int dfs(int i, int d) {
  if (!c[i]) {
    c[i] = d;
    for (int j : g[i]) dfs(j, d ^ 3);
  }
  return c[i];
}
int main() {
  ios::sync_with_stdio(0), cin.tie(0);
  int n, c;
  cin >> n;
  for (int i = 0; i++ < n;)
    for (int j = 0; j++ < 2;) {
      cin >> c;
      int& d = k[j - 1][c];
      if (d) {
        g[d].push_back(i);
        g[i].push_back(d);
        d = 0;
      } else
        d = i;
    }
  for (int i = 0; i++ < n;) cout << (dfs(i, 1) & 1 ? 'b' : 'r');
}
