def threeSum(arr, target):

arr.sort()

size=len(arr)

max=float('inf')

res=0

i=0

while i<size:

start = i + 1

end= size -1

while start < end:

sum = arr[i] + arr[start] + arr[end]

diff = abs(sum - target)

if diff == 0:

return sum

if diff < max:

max = diff

res = sum

if sum <= target:

start += 1

else:

end -= 1

i=i+1

return res

arr= [7,12,3,1,2,-6,5,-8,6]

target = 0

print(threeSum(arr,target))