i = 0
times = []
n = int(input())
while i < n:
start, end = input().split()
times.append((start, 'start'))
times.append((end, 'zend'))
i += 1
times = sorted(times)
print(times)
aSA9IDAKdGltZXMgPSBbXQpuID0gaW50KGlucHV0KCkpCndoaWxlIGkgPCBuOgogIHN0YXJ0LCBlbmQgPSBpbnB1dCgpLnNwbGl0KCkKICB0aW1lcy5hcHBlbmQoKHN0YXJ0LCAnc3RhcnQnKSkKICB0aW1lcy5hcHBlbmQoKGVuZCwgJ3plbmQnKSkKICBpICs9IDEKCnRpbWVzID0gc29ydGVkKHRpbWVzKQpwcmludCh0aW1lcyk=