X and Y are the number of electrons involved, respectively during the oxidation of I^- to I_2 and S^2- to S by acidified K_2 Cr_2 O_7. The value of X…

X and Y are the number of electrons involved, respectively during the oxidation of $\displaystyle \mathrm{I}^{-}$to $\displaystyle \mathrm{I}_2$ and $\displaystyle \mathrm{S}^{2-}$ to S by acidified $\displaystyle \mathrm{K}_2 \mathrm{Cr}_2 \mathrm{O}_7$. The value of $\displaystyle \mathrm{X}+\mathrm{Y}$ is $\displaystyle \_\_\_\_$.