import strutils, sequtils, algorithm

const n = 3
var prsn = newSeq[tuple[name: char, h, w: int]](n)


for i in 0 ..< n:
  (prsn[i].h, prsn[i].w) = stdin.readLine.split.map parseInt
  prsn[i].name = ('A'.int + i).chr

for p in sortedByIt(prsn, (-it.h, it.w)):
  echo p.name