!N = 2mn + m^2 = (2n + m)m
!(N/m-m) = 2n

!N = 4an + 4a^2 = 4a(n + a)
!N/4 = a(n+a)


program main
    implicit none
    
    integer(16) :: n
    
    integer(16) :: i
    
    read *, n
    
    if (n < 3) then
        print '(A)', "-1"
        stop
    end if
    
    if (n == 4) then
        print '(A)', "-1"
        stop
    end if
    
    if (mod(n, 2) == 1) then
        print '(A)', "1"
        stop
    end if
    
    if (mod(n, 4) == 0) then
        print '(A)', "1"
        stop
    end if
    
    print '(A)', "-1"
end program main