diff --git a/lab2CA.srcs/sources_1/new/BasicModules.v b/lab2CA.srcs/sources_1/new/BasicModules.v
index 2273c97..5cdafdd 100644
--- a/lab2CA.srcs/sources_1/new/BasicModules.v
+++ b/lab2CA.srcs/sources_1/new/BasicModules.v
@@ -423,4 +423,22 @@ module register(input wire clk, reset,
         end
     end
 
+endmodule
+
+module twos_compliment_9bit(
+    input wire [8:0] A,
+    output wire [8:0] C);
+    
+    wire [8:0] B;
+    
+    not_9bit not0(
+        .A(A),
+        .B(B));
+        
+    adder_9bit adder0(
+        .A(B),
+        .B(9'b000000000),
+        .Cin(1'b1),
+        .Sum(C));
+
 endmodule
\ No newline at end of file