#include <bits/stdc++.h>
using namespace std;
const int N = 1e6 + 40;
int v[N], x[N], ct, al[N], col[N], n, lu[N], lv[N];
int read() {
  int sum = 0, fg = 1;
  char c = getchar();
  while (c < '0' || c > '9') {
    if (c == '-') fg = -1;
    c = getchar();
  }
  while (c >= '0' && c <= '9') {
    sum = sum * 10 + c - '0';
    c = getchar();
  }
  return sum * fg;
}
inline void add(int u, int V) {
  v[++ct] = V;
  x[ct] = al[u];
  al[u] = ct;
}
inline void dfs(int u, int tw) {
  col[u] = tw;
  for (int i = al[u]; i; i = x[i])
    if (col[v[i]] == -1) dfs(v[i], tw ^ 1);
}
int main() {
  n = read();
  for (int i = 1; i <= n; i++) col[i] = -1;
  for (register int i = 1, x, y; i <= n; i++) {
    x = read();
    y = read();
    if (lu[x]) {
      add(lu[x], i);
      add(i, lu[x]);
      lu[x] = 0;
    } else
      lu[x] = i;
    if (lv[y]) {
      add(lv[y], i);
      add(i, lv[y]);
      lv[y] = 0;
    } else
      lv[y] = i;
  }
  for (register int i = 1; i <= n; i++)
    if (col[i] == -1) dfs(i, 0);
  for (register int i = 1; i <= n; i++)
    if (col[i] == 0)
      cout << "b";
    else
      cout << "r";
  return 0;
}
