Simon AI displays paired event labels by interleaving characters from two strings. Given strings a and b, return a new string formed by taking one character from a, then one from b, repeating while both strings have characters remaining. Append the unused suffix of the longer string unchanged.
Implement merge_alternating(a, b).
a and b.a and b, in alternating order whenever both strings still have characters.a.def merge_alternating(a, b):