module main;
reg [31:0] a, b, c;
initial begin
a = 1;
b = 1;
b[2] = 1'bx;
c = a << b;
//$display( "a: %b, b: %b, c: %b", a, b, c );
if (c != 32'bx) $display("FAILED");
else $display("PASSED");
end
endmodule