Type Casting in Java

Could anyone explain why short(100000) is -31072 as said in p.48 of java-notes.The article says that "the value -31072 is obtained by taking the the 4 byte int 100000 and throwing away two of these bytes to obtain a short".

The code in the article related to the question is:

int A;
short B;
A = 17;
B = (short)A;