# Compute conditional probability for a decision analysis network

I have to resolve an exercise for decision analysis network.

I have the following decision tree for that decision analysis network:

$$\begin{array}{l} G&\to&Y&\to&D&\to&X&\to&U% \end{array}$$

G, Y and X are chance nodes.
D is a decision node.
U is an utility node.

I don't need to compute probability of D because it is a decision node (this is why probability of X node is $$P(x|y)$$ instead of $$P(x|d)$$.

I know $$P(x)$$, $$P(y|x)$$ and $$P(g)$$ and I need to compute $$P(y|g)$$

How can I compute it?