def solution(sizes):
maxx = 0
maxy = 0
sort = []
for size in sizes:
if size[0] < size[1]:
tmp = size[0]
size[0] = size[1]
size[1] = tmp
sort.append([size[0], size[1]])
for a in sort:
if a[0] > maxx:
maxx = a[0]
if a[1] > maxy:
maxy = a[1]
answer = maxx * maxy
return answer
sizes = [[60, 50], [30, 70], [60, 30], [80, 40]]
print(solution(sizes))
