nums = list(map(int, input().split()))
nums[:] = sorted(nums)
list1 = []
l = 0
r = len(nums)-1
mins = nums[l]+nums[r]
while r>l:
if abs(nums[l] + nums[r])<abs(mins):
mins = nums[l] + nums[r]
list1.append([nums[l],nums[r]])
elif abs(nums[l])>abs(nums[r]):
l+=1
else:
r -=1
print(' '.join(map(str,list1)),mins)
#这是复杂度为n的双指针
