Solve this following

If $\vec{a}=x \hat{i}+2 \hat{j}-z \hat{k}$ and $\overrightarrow{\mathrm{b}}=3 \hat{\mathrm{i}}-\mathrm{y} \hat{\mathrm{j}}+\hat{\mathrm{k}}$ are two equal vectors the $x+y+z=?$