from sys import stdin
import re
lines = stdin.readlines()

def getint():
  res = lines.pop(0)
  intre = r'(0|(-?[1-9][0-9]*))'
  assert(re.fullmatch(intre + r'\n', res))
  return int(res.strip())

def getints():
  res = lines.pop(0)
  intre = r'(0|(-?[1-9][0-9]*))'
  assert(re.fullmatch(r'{0}( {0})*\n'.format(intre), res))
  return list(map(int, res.strip().split()))

n = getint()
assert(3 <= n <= 200)
for _ in range(n):
  a = getints()
  assert(len(a) == 2)
  assert(1 <= a[0] < a[1] <= 10**9)
assert(len(lines) == 0)