program main
    implicit none
    integer::x,y
    read(*,*)x,y
    ! x,x
    if(x==y)then
        print*,0
        return
    end if
    ! x,0
    if(y==0)then
        print*,1
        return
    end if
    ! 0,x
    if(x==0)then
        print*,2
        return
    end if
    !x,-x
    if(x+y==0)then
        print*,3
        return
    end if
    print*,-1
end program