```
class Solution(object):
def twoSum(self, numbers, target):
"""
:type numbers: List[int]
:type target: int
:rtype: List[int]
"""
if not numbers:
return []
ind1 = 0
ind2 = len(numbers) - 1
while ind1 < ind2:
sumv = numbers[ind1] + numbers[ind2]
if sumv == target:
return [ind1+1, ind2+1]
elif sumv > target:
ind2-=1
else:
ind1+=1
```