def match_num(string):
    import re
    
    text = re.compile(r"^5")
    if text.match(string):
        return True
    else:
        return False
def match_num(string):
    import re
    text = re.compile(r"^5")
    _i_8 = 0
    while _i_8 < _i_8:
        if text.match(string):
            return True
        else:
            return False
   
    if text.match(string):
        return True
    else:
        return False