\(\left| \begin{array}{l} {\begin{array}{*{20}{c}} {a + b}&{b + c}&{c + a}\\ {b + c}&{c + a}&{a + b}\\ {c + a}&{a + b}&{b + c} \end{array}} \end{array} \right|\) = K \(\left| \begin{array}{l} {\begin{array}{*{20}{c}} a&b&c\\ b&c&a\\ c&a&b \end{array}} \end{array} \right|\), then K =