------
## 最终结论
```python
def count_samepair(list1, list2, list3):
    count = 0
    for a, b, c in zip(list1, list2, list3):
        if a == b == c:
            count += 1
    return count

# Test cases
assert count_samepair([1,2,3,4,5,6,7,8],[2,2,3,1,2,6,7,9],[2,1,3,1,2,6,7,9]) == 3
assert count_samepair([1,2,3,4,5,6,7,8],[2,2,3,1,2,6,7,8],[2,1,3,1,2,6,7,8]) == 4
assert count_samepair([1,2,3,4,2,6,7,8],[2,2,3,1,2,6,7,-8],[2,-1,-3,-1,-2,-6,-7,-8]) == 5
```