class Solution:
    def mergeAlternately(self, word1: str, word2: str) -> str:
        word3 = ""
        j = i = 0
        len1 = len(word1)
        len2 = len(word2)
        while j < len1 or i < len2:
            if j < len1:
                word3 += "".join(word1[j])
                j += 1
            
            if i < len2:
                word3 += "".join(word2[i])
                i += 1

        return word3