Vector Algebra

\(\vec{a}=4 \hat{i}+13 \hat{j}-18 \hat{k}, \vec{b}=\hat{i}-2 \hat{j}+3 \hat{k}\) and \(\vec{c}=2 \hat{i}+3 \hat{j}-4 \hat{k}\) are three vectors such that \(\vec{a}=x \vec{b}+y \vec{c}\), then \(x+y=\)