If \(\overset{⃗}{a},\overset{⃗}{b},\overset{⃗}{c}\) are three vectors such that \(\overset{⃗}{a}⟂(\overset{⃗}{b}+\overset{⃗}{c}),\overset{⃗}{b}⟂(\overset{⃗}{c}+\overset{⃗}{a}),\) and \(\overset{⃗}{c}⟂(\overset{⃗}{a}+\overset{⃗}{b})\) and \(|\overset{⃗}{a}| = 1,|\overset{⃗}{b}| = 2,|\overset{⃗}{c}| = 3\), then \(|\overset{⃗}{a}+\overset{⃗}{b}+\overset{⃗}{c}|\) is...