# Decay Feynman diagram

$$D^0 \to K^+ +\pi^- + \pi^0 + \pi^0$$ cannot occur by first order weak interactions. Could anybody help me confirm this? What I currently have is that the initial charm goes to anti-strange and the anti-up goes to anti-down, both through the $W$ boson.

Is there something wrong with this process? (it will admittedly be suppressed by $|V_{su}|^2\approx \frac{1}{20}$, i.e. "doubly cabbibo suppressed")