(define (System.out.println x)
  (begin
    (write x)
    (newline)
  )
)

(let (
      (SA (symbol->string (read)))
      (PA (read))
      (XA (symbol->string (read)))
      (SB (symbol->string (read)))
      (PB (read))
      (XB (symbol->string (read)))
     )
  (cond
    ((= PA PB) (System.out.println "-1"))
    ((> PA PB) (System.out.println SA))
    ((< PA PB) (System.out.println SB))
  )
)