diff --git a/ES/Lab/Lab3/add128bit.asm b/ES/Lab/Lab3/add128bit.asm
index 38cce39..0013637 100644
--- a/ES/Lab/Lab3/add128bit.asm
+++ b/ES/Lab/Lab3/add128bit.asm
@@ -21,7 +21,7 @@ UP
 	LDR R4, [R1], #4
 	LDR R5, [R2], #4
 	ADCS R6, R5, R4
-	SUB R3, R1
+	SUB R3, #1
 	TEQ R3, #0
 	BNE UP;