Simplify : ${\left[{\left\{\right(625{)}^{\frac{-1}{2}}\}}^{\frac{-1}{4}}\right]}^2$

${\left[{\left\{\right(625{)}^{\frac{-1}{2}}\}}^{\frac{-1}{4}}\right]}^2=(625{)}^{\frac{-1}{2}\times \left(\frac{-1}{4}\right)\times 2}=(625{)}^{\frac{1}{4}}=(5^4{)}^{\frac{1}{4}}=5^{4\times \frac{1}{4}}=5^1=5$