Leetcode 944. Delete Columns to Make Sorted

class Solution:
    def minDeletionSize(self, A: List[str]) -> int:
        ans = 0
        for j in range(len(A[0])):
            t = []
            for a in A:
                t.append(a[j])
            if sorted(t) != t:
                ans += 1
        return ans