def findCommonPart(s1, s2):
  common = (max(s1[0], s2[0]), min(s1[1], s2[1]))
  if common[0] > common[1]:
    return None
  return common

def dist(s):
  return abs(s[1] - s[0])

def solution(segments):
  target = 0
  otherTarget = None
  common = segments[0]
  for i, s in enumerate(segments[1:], 1):
    newCommon = findCommonPart(common, s)
    if not newCommon:
      if not otherTarget:
        otherTarget = i
      else:
        return target
    else:
      if dist(newCommon) < dist(common):
        target = i

      common = newCommon

  return otherTarget