with open("task4-input.txt", "r") as file:
    string = file.readline()
    result = ''
    print(string)
    print(ord('D') - ord('C'))
    if len(string) != 5 or string[2] != '-' or string[0]<'A'or string[0]>'H' or string[3]<'A'or string[3]>'H' or string[1]<'1'or string[1]>'8' or string[4]<'1' or string[4]>'8':
        result = 'ERROR'
    elif abs((ord(string[0]) - ord(string[3])) * (int(string[1]) - int(string[4]))) == 2:
        result = 'YES'
    else:
        result = 'NO'

with open("task4-output.txt", "w") as file:
    file.write(result)