module adder3bit(
	input [2:0] A,
	input [2:0] B,
	output [3:0] C
);


wire c1, c2, c3, c4;
ha a0(A[0], B[0], C[0], c1);
fa a1(A[1], B[1], c1, C[1], c2);
fa a2(A[2], B[2], c2, C[2], C[3]);

endmodule