Initialize A= 1 B=2 C=3.
= is an assignment symbol.
Then A=B is to assign the value of b to a, then A=2.
Then B=C is to assign the value of c to b, then C=3.
Then C=A means that before assigning the value of a to c, a becomes 2, so c=2.
Print C, B, A: This is an output statement, and the three numbers of C B A are 2, 3 and 2 respectively.