class String
def isalpha?
!!(self =~ /^[[:alpha:]]+$/)
end
def isdigit?
!!(self =~ /^\d+$/)
end
end
print 'f'.isalpha?, ' ', '1'.isalpha?, "\n"
print 'f'.isdigit?, ' ', '1'.isdigit?
Y2xhc3MgU3RyaW5nCglkZWYgaXNhbHBoYT8KCQkhIShzZWxmID1+IC9eW1s6YWxwaGE6XV0rJC8pCgllbmQKCWRlZiBpc2RpZ2l0PwoJCSEhKHNlbGYgPX4gL15cZCskLykKCWVuZAplbmQKIApwcmludCAnZicuaXNhbHBoYT8sICcgJywgJzEnLmlzYWxwaGE/LCAiXG4iCnByaW50ICdmJy5pc2RpZ2l0PywgJyAnLCAnMScuaXNkaWdpdD8=