!phi1=@val(%0)
!rho1=@val(%2)
!phi2=@val(%1)
!rho2=@val(%3)
'rndseed 123 
'uncomment above to get specific seed
smpl @first @first+1
series y = 0
smpl @first @last
series u = nrnd
smpl @first+2 @last
series y = !phi1*y(-1) + !phi2*y(-2) + u + !rho1*u(-1) + !rho2*u(-2)