You are given three strings: s1, s2, and s3. In one operation you can choose one of these strings and delete its rightmost character. Note that you cannot completely empty a string.
Return the minimum number of operations required to make the strings equal. If it is impossible to make them equal, return -1.
Example 1:
Input: s1 = "abc", s2 = "abb", s3 = "ab"
Output: 2
Explanation: Deleting the rightmost character from both s1 and s2 will result in three equal strings.
Example 2:
Input: s1 = "dac", s2 = "bac", s3 = "cac"
Output: -1
Explanation: Since the first letters of s1 and s2 differ, they cannot be made equal.
Constraints:
1 <= s1.length, s2.length, s3.length <= 100s1, s2 and s3 consist only of lowercase English letters."abc" "abb" "ab" "dac" "bac" "cac"