BEGIN {
  path = "data/lookup.txt"
  while ((status = (getline line < path)) > 0) {
    split(line, fields); city[fields[1]] = fields[2]
  }
  close(path)
  if (status < 0) { print "lookup read error"; exit 1 }
}
{ print $1, ($2 in city ? city[$2] : "UNKNOWN") }