a bit-flip error on one of the two pairs (a1nbuH +aIr by +a2nb2h +a2y bay (alr bi+aRbil t a2yb2h t a2yb2y (a,HbiH+a2p)(a, b# +a2Hbir )o)ae(0+0)),ae2 +(a,HbtH+a2v biv (atHbi* ++a2rb2h)))aei2e ) ae(+0> (a1 )(a, biH +a2hbiv)lOy 2 ae ae i(6+b) Iv iy t a 2H2H b +(ab+1+a212n)(a+b+ IH ir t a2y b2h )oae(0+8) i20 eA bit-flip error on one of the two pairs： 1 1 1 1 2 2 2 2 1 1 1 1 2 2 2 2 ( ) ( ) 0 H H V V H H V V V H H V V H H V a b a b a b a b a b a b a b a b + + + + + + + + + + + + + + + + + + + + + + ( ) 2 1 1 2 2 1 1 2 2 2 ( ) 1 1 2 2 1 1 2 2 2 ( ) 1 1 2 2 1 1 2 2 1 1 2 2 1 1 ( )( ) 0 ( )( ) 0 ( )( ) 0 ( )( i i H H V V V H H V a b i i H H V V H V V H a b i i V V H H V H H V a b V V H H H V a b a b a b a b e e a b a b a b a b e e a b a b a b a b e e a b a b a b a                + + + + + + + + +  + + + + + + + + +  + + + + + + + + +   + + + + + + + + + + + + + + + + + + ( ) 2 2 2 ) 0 i i V H a b b e e      + + +  