diff --git a/SM2-WWMM-(2).md b/SM2-WWMM-(2).md
index 67d541d..ddf48e9 100644
--- a/SM2-WWMM-(2).md
+++ b/SM2-WWMM-(2).md
@@ -106,7 +106,7 @@ $t_0=t_0 - a_1$
 	MOVQ acc0, DX           \
 	SHLQ $32, AX            \  // AX = L(acc0 * 2^32), low part
 	SHRQ $32, DX            \  // DX = H(acc0 * 2^32), high part
-	\// calculate the negative part: [1, -0x100000000, 0, -0x100000000] * acc0
+	\// calculate the negative part: [1, -0x100000000, 0, -0x100000000] * acc0 + [0, acc3, acc2, acc1]
 	SUBQ AX, acc1            \ 
 	SBBQ DX, acc2            \
 	SBBQ AX, acc3            \