test.py

def solution(S, T):
    S = 'a10'
    T = '10a'

    any_lenth_S = 0
    any_lenth_T = 0

    numbers = '0123456789'

    finish = False
    result = True

    while not finish:
        if any_lenth_S!=0 or any_lenth_T!=0:
            any_lenth_S -= min(any_lenth_S, any_lenth_T)
            any_lenth_T -= min(any_lenth_S, any_lenth_T)
            skip_len = 0

            if any_lenth_S > any_lenth_T:
                while T[skip_len] not in numbers and skip_len < len(T) and any_lenth_S > skip_len:
                    skip_len += 1
                if skip_len == len(T):
                    return(False)
                else:
                    any_lenth_S -= skip_len - 1
                    T = T[skip_len-1:]
            else:
                while S[skip_len] not in numbers and skip_len < len(S) and any_lenth_T > skip_len:
                    skip_len += 1
                if skip_len == len(S):
                    return(False)
                else:
                    any_lenth_T -= skip_len - 1
                    S = S[skip_len-1:]

            print(S, any_lenth_S)
            print(T, any_lenth_T)

            if S[0] in numbers:
                number_len = 0
                while S[number_len] in numbers and numbers<len(S):
                    number_len += 1
                any_lenth_S = int(S[:number_len-1])
                S = S[number_len:]

            if T[0] in numbers:
                number_len = 0
                while T[number_len] in numbers and numbers<len(S):
                    number_len += 1
                any_lenth_T = int(T[:number_len-1])
                T = T[number_len:]

            print(S, any_lenth_S)
            print(T, any_lenth_T)

        else:
            if S[0] in numbers or T[0] in numbers:
                if S[0] in numbers:
                    number_len = 0
                    while S[number_len] in numbers and numbers<len(S):
                        number_len += 1
                    any_lenth_S = int(S[:number_len-1])
                    S = S[number_len:]

                if T[0] in numbers:
                    number_len = 0
                    while T[number_len] in numbers and numbers<len(S):
                        number_len += 1
                    any_lenth_T = int(T[:number_len-1])
                    T = T[number_len:]

                print(S, any_lenth_S)
                print(T, any_lenth_T)
            else:
                if S[0]!=T[0]:
                    return(False)

    return S or T




print solution('A2Le', '2pL1')
print solution('a10', '10a')
print solution('ba1', '1Ad')
print solution('3x2x', '8')