Explanation:Both strings have the same length. Characters are merged alternately: 'a' from word1, 'p' from word2, 'b' from word1, 'q' from word2, 'c' from word1, 'r' from word2.
Example 2:
Input:word1 = "ab", word2 = "pqrs"
Output:"apbqrs"
Explanation:word2 is longer than word1. After 'a', 'p', 'b', 'q' are merged, 'word1' is exhausted. The remaining 'rs' from 'word2' are appended to the end.
Example 3:
Input:word1 = "abcd", word2 = "pq"
Output:"apbqcd"
Explanation:word1 is longer than word2. After 'a', 'p', 'b', 'q' are merged, 'word2' is exhausted. The remaining 'cd' from 'word1' are appended to the end.