program main
    implicit none
    
    integer(16) :: n
    
    integer(16) :: i
    
    read *, n
    
    do i = 1, int(sqrt(real(n)), 16)
        if (mod(n, i) == 0) then
            if (mod(n / i - i, 2) == 0) then
                print '(A)', "1"
                stop
            end if
        end if
    end do
    
    print '(A)', "-1"
end program main