' X ' is the number of acidic oxides among $\mathrm{VO}_2, \mathrm{~V}_2 \mathrm{O}_3, \mathrm{CrO}_3, \mathrm{~V}_2 \mathrm{O}_5$ and $\mathrm{Mn}_2 \mathrm{O}_7$. The primary valency of cobalt in $\left.\left[\mathrm{Co}\left(\mathrm{H}_2 \mathrm{NCH}_2 \mathrm{CH}_2 \mathrm{NH}_2\right)_3\right)\right]_2\left(\mathrm{SO}_4\right)_3$ is Y . The value of $\mathrm{X}+\mathrm{Y}$ is ___________.