class Solution:
def twoSum(self, numbers: List[int], target: int) -> List[int]:
n = len(numbers)
if n < 2:
return []
left, right = 0, n-1
while left < right:
if numbers[left] + numbers[right] == target:
return [left+1, right+1]
elif numbers[left] + numbers[right] > target:
right -= 1
else:
left += 1
