#include <bits/stdc++.h>
const int N = 2e6 + 7;
int n, lasx[N], lasy[N], tot, to[N], nex[N], head[N];
char ans[N];
void add(int x, int y) {
  to[++tot] = y;
  nex[tot] = head[x];
  head[x] = tot;
}
void dfs(int u, bool flag) {
  if (flag)
    ans[u] = 'b';
  else
    ans[u] = 'r';
  for (int i = head[u]; i; i = nex[i])
    if (ans[to[i]] == '$') dfs(to[i], flag ^ 1);
}
int main() {
  int n;
  scanf("%d", &n);
  for (int i = 1, x, y; i <= n; ++i) {
    ans[i] = '$';
    scanf("%d%d", &x, &y);
    if (lasx[x])
      add(lasx[x], i), add(i, lasx[x]), lasx[x] = 0;
    else
      lasx[x] = i;
    if (lasy[y])
      add(lasy[y], i), add(i, lasy[y]), lasy[y] = 0;
    else
      lasy[y] = i;
  }
  for (int i = 1; i <= n; ++i)
    if (ans[i] == '$') dfs(i, 1);
  for (int i = 1; i <= n; ++i) printf("%c", ans[i]);
}
