------
## 最终结论
```python
def minDeletionSize(A):
    if not A or not A[0]:
        return 0

    num_deletions = 0  # Initialize deletion counter

    # Loop through each column index
    for col in range(len(A[0])):
        # Check each row starting from the second row
        for row in range(1, len(A)):
            if A[row][col] < A[row - 1][col]:  # Compare current row with previous row
                num_deletions += 1  # Increment deletion counter if out of order
                break  # No need to check further rows for this column

    return num_deletions  # Return the total count of deletions required

# Example usage:
print(minDeletionSize(["ca","bb","ac"])) # Output: 1
print(minDeletionSize(["xc","yb","za"])) # Output: 0
print(minDeletionSize(["zyx","wvu","tsr"])) # Output: 3
```