#include <bits/stdc++.h>
using namespace std;
int col[200010];
int lstx[200010], lsty[200010];
struct Edge {
  int v, nxt;
} e[400010];
int tot;
int first[200010];
void build(int u, int v) {
  e[++tot] = (Edge){v, first[u]};
  first[u] = tot;
  return;
}
void dfs(int u, int now) {
  if (col[u]) return;
  col[u] = now;
  for (int i = first[u]; i; i = e[i].nxt) dfs(e[i].v, now ^ 1);
  return;
}
int main() {
  int n;
  scanf("%d", &n);
  for (int i = 1; i <= n; i++) {
    int x, y;
    scanf("%d %d", &x, &y);
    if (lstx[x]) {
      build(lstx[x], i);
      build(i, lstx[x]);
      lstx[x] = 0;
    } else
      lstx[x] = i;
    if (lsty[y]) {
      build(lsty[y], i);
      build(i, lsty[y]);
      lsty[y] = 0;
    } else
      lsty[y] = i;
  }
  for (int i = 1; i <= n; i++) {
    dfs(i, 0);
    if (col[i])
      printf("b");
    else
      printf("r");
  }
  printf("\n");
  return 0;
}
