auto.arima(IR.ts)
Series: IR.ts
ARIMA(1,0,0)(2,1,0)[12]

Coefficients:
         ar1     sar1    sar2
      0.5896  -0.2163  0.3272
s.e.  0.0972   0.1192  0.1318

sigma^2 = 7.427:  log likelihood = -175.04
AIC=358.08   AICc=358.68   BIC=367.19
是系统自动输出的模型，请问我要怎么修改呀