program main
  implicit none
  integer*8::x,y,z,a,b,c,d,e,f,ab,cd
  integer*8::i
  read *,x,y,z

  a = x*y
  b = y-x
  c = y*z
  d = z-y

!  ab = gcd(a,b)
!  cd = gcd(c,d)
!  a = a/ab
!  b = b/ab
!  c = c/cd
!  d = d/cd

  call lcm_fraction(a,b,c,d,e,f)
  print '(i0,"/",i0)',e,f
contains
  recursive function gcd(a,b) result(c)
    integer*8::a,b,c
    if(b.eq.0) then
       c = a
    else
       c = gcd(b,MOD(a,b))
    end if
  end function gcd
  function lcm(a,b) result(c)
    integer*8,intent(in)::a,b
    integer*8::c
    c = (a/gcd(a,b))*b
  end function lcm
  subroutine lcm_fraction(a,b,c,d,e,f)
    ! e/f=lcm(a/b,c/d)
    !
    ! l = a/b*X = c/d*Y = lcm(a/b,c/d)
    ! b*d*l = a*d*X = c*b*Y = lcm(a*d, b*c)
    ! l = lcm(a*d, b*c)/(b*d)
    integer*8::a,b,c,d,e,f
    integer*8::adbc,bd,gcd_adbcbd
    adbc = lcm(a*d,b*c)
    bd = b*d
    gcd_adbcbd = gcd(adbc, bd)
    e = adbc/gcd_adbcbd
    f = bd/gcd_adbcbd
  end subroutine lcm_fraction
end program main