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))