Examples:
Input: set1 [] = {"abcdefgh", "pythonengineering", "lmnopqrst", "abc"} set2 [] = {"ijklmnopqrstuvwxyz", "abcdefghijklmnopqrstuvwxyrst." "} Output: 7 The total complete pairs that are forming are :" abcdefghijklmnopqrstuvwxyz "" abcdefghabcdefghijklmnopqrstuvwxyz "" abcdefghdefghijklmnopqrstuvwxyz "" pythonengineeringabcdefghijklmnopqrstuvwxyz "" lmnopqrstabcdefghijklmnopqrstuvwxyz "" abcabcdefghijklmnopqrstuvwxyz "" abcdefghijklmnopqrstuvwxyz "we have the solution this problem, please refer to the Set data structure . The approach is very simple,
 Consider all pairs of strings, concatenate them one by one and convert them to a set.
 Now add all the alphabets in the concatenated string to the set one by one. Since the set contains unique values, so if the set length is 26, it means that the set contains all 26 English alphabets.

Exit:
7