In a single-parity-check code, a single parity bit is appended

In a single-parity-check code, a single parity bit is appended to a block of k message bits (m1, m2,,.., mk,). The single parity bit b1 is chosen so that the code word satisfies the even parity ride:
m1 + m2 + . . . + mk + b1 = 0, mod 2 for k = 3, set up the 2k possible code words in the code defined by this rule.