# Calculate probability in graphical model

I have the following graphical model, in which I wish to compute $$p(Intelligence = 1|Letter = 1, SAT = 1)$$

I tried using Bayes, and also just without Bayes as $$p(D,I,G,L,S)=p(D)p(I)p(G|D,I)p(S|I)p(L|G)$$ but im stuck, here, when I for example trie to calculate $$p(G|D,I)$$.