Morgan and String

py

__author__ = 'abdujabbor'


def find_lex_min_string(s1, s2):
    result = ''
    i = 0
    j = 0
    while i < len(s1) and j < len(s2):
        if s1[i:] < s2[j:]:
            result += s1[i]
            i += 1
        elif s2[j:] < s1[i:]:
            result += s2[j]
            j += 1

    if i < len(s1):
        result += s1[i:]

    if j < len(s2):
        result += s2[j:]

    return result


t = int(input())

for i in range(t):
    print(find_lex_min_string(input(), input()))