**A. 376.** Is it possible to obtain the array (5,13,42) starting from (1,21,42) by repeating the following steps: It is allowed to swap any two numbers in an array of three numbers (*a*,*b*,*c*), or replace the array by (*a*,*b*,2*a*+2*b*-*c*).

(5 points)

**B. 3822.** Is it possible to obtain the array (1,3,8) starting from (2,5,13) by repeating the following steps: It is allowed to swap any two numbers in an array of three numbers (*a*,*b*,*c*), or replace the array by (*a*,*b*,2*a*+2*b*-*c*).

(4 points)