Is booth algorithm for multiplication only for multiplying 2 negative numbers (-3 * -4) or one positive and one negative number (-3 * 4) ? Whenever i multiply 2 positive numbers using booth algorithm i get a wrong result.

example : 5 * 4

A = 101 000 0 // binary of 5 is 101

S = 011 000 0 // 2's complement of 5 is 011

P = 000 100 0 // binary of 4 is 100

x = 3

y = 3

m = 5

-m = 2's complement of m

r = 4

1. After right shift of P by 1 bit 0 000 100

2. After right shift of P by 1 bit 0 000 010

3. P+S = 011 001 0

   After right shift by 1 bit 0 011 001

4. Discarding the LSB 001100

   But that comes out to be the binary of 12 . It should have been 20(010100)