PROBLEM TO BE SOLVED: To prevent a delay in the parity circuit and the number of elements thereof from being increased and to avoid a coupling coefficient from being exponentially increased with respect to an input number.
SOLUTION: The parity circuit has an input layer 1 that receives a value of +1 or -1, an output layer 2 that outputs a value of +1 or -1 and an intermediate layer 3 that configures a coupling strength to satisfy an input output relationship. Input sections 1a-1c receive a value of +1 or -1, respectively. The input layer 1 delivers the value to each of elements 3a-3c as it is. A sign of + or - of input sections of each of the elements 3a-3c depicts a coupling strength, the value received by each input section is multiplied with a value of the coupling strength and a result of the majority decision of the products after that is outputted to an element 2a of the output layer 2. The output value is +1 or -1.