import re
import sys


def line_contains(line):
    return re.match("(^(Mt ([1-9]|[1][0-9]|[2][0-8])))?(^(Mk ([1-9]|[1][0-6])))?(^(Łk ([1-9]|[1][0-9]|[2][0-4])))?(^(J ([1-9]|[1][0-9]|[2][0-2])))?(\, [1-9]?[0-9])", line)


for line in sys.stdin:
    if line_contains(line):
        print("yes")
    else:
        print("no")