{$MODE OBJFPC}
uses math;
type
    point = record
        x,y : integer;
    end;
var
    n,q : integer;
    maxx,minx,maxy,miny : integer;
    p : array[1..11] of point;
function kt ( i : integer) : boolean;
begin
    if (p[i].x = minx) or (p[i].x = maxx) then
        begin
            if (p[i].y >= miny) and (p[i].y <= maxy) then exit(true);
        end;
    if (p[i].y = miny) or (p[i].y = maxy) then
        begin
            if (p[i].x >= minx) and (p[i].x <= maxx) then exit(true);
        end;
    exit(false);
end;
procedure xuli;
var
    i : integer;
    flag : boolean;
begin
    readln(n);
    maxx:= -trunc(1e4);
    minx:= trunc(1e4);
    maxy:= -trunc(1e4);
    miny:= trunc(1e4);
    for i:=1 to n do
        with p[i] do
            begin
                readln(x,y);
                maxx:= max(maxx,x);
                minx:= min(minx,x);
                maxy:= max(maxy,y);
                miny:= min(miny,y);
            end;
    flag:= true;
    for i:=1 to n do
        with p[i] do
            if kt(i) = false then
                begin
                    flag:= false;
                    break;
                end;
    if flag = true then writeln('YES')
    else writeln('NO');

end;
BEGIN
    readln(q);
    while (q > 0) do
        begin
            xuli;
            dec(q);
        end;
END.