def group_check(s):
    while '()' in s or '{}' in s or '[]' in s:
        s=s.replace('()','')
        s=s.replace('{}','')
        s=s.replace('[]','')
    return len(s)==0
    
    
    
print(group_check("()"))
print(group_check("({"))
print(group_check("({}{}[])"))