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

(let (
      (N (read))
     )
  (if (= N 1)
      (System.out.println 1)
      (let loop(
                (i 1)
                (Sum 0)
               )
        (if (> i N)
            (System.out.println (gcd N Sum))
            (loop (+ i 1) (+ Sum i))
        )
      )
  )
)