import re import sys def is_pokemon(line: str) -> bool: # Defining lowercase and uppercase sets, with Polish diacritic letters included. lowercase = "a-ząćęłńóśźż" uppercase = "A-ZĄĆĘŁŃÓŚŹŻ" # Note: I tried to use a single regex pattern as requested. # It turned to be kinda complicated! It relies on preventing identical cases appearing in a row, thus switching case. p = re.compile(fr'^([{uppercase}]?(?:[{lowercase}][{uppercase}])+[{lowercase}]?)') return bool(p.match(line)) if __name__ == "__main__": for line in sys.stdin: stripped_line = line.strip() print("yes" if is_pokemon(stripped_line) else "no")