module CLA_4bit(
    output [3:0] S,
    output Cout,
    input [3:0] A,B,
    input Cin
    );
    wire [3:0] G,P,C;

    assign G = A & B;
    assign P = A ^ B;
    assign C[0] = Cin;
    assign C[1] = G[0] | (P[0] & C[0]);
    assign C[2] = G[1] | (P[1] & G[0]) | (P[1] & P[0] & C[0]);
    assign C[3] = G[2] | (P[2] & G[1]) | (P[2] & P[1] & G[0]) |             (P[2] & P[1] & P[0] & C[0]);
    assign Cout = G[3] | (P[3] & G[2]) | (P[3] & P[2] & G[1]) | (P[3] & P[2] & P[1] & G[0]) |(P[3] & P[2] & P[1] & P[0] & C[0]);
    assign S = P ^ C;

endmodule