import re

def int_cast(integers):
    if not integers:
        return 0
    else:
        value = int(integers)
        return value

def get_string(input_str):
    regex = r"([A-z]+)([0-9]+)"
    matches = re.findall(regex, input_str, re.MULTILINE)
    letter_string = ""
    for match in matches:
        letters, integers = match
        letter_string += int_cast(integers)*letters
    return letter_string


if __name__=="__main__":
    input_str = "Z3f4g7d10a6c0"
    print(get_string(input_str))