program intersection;
const
    eps = 0.000001;
    maxLines = 500;
    inputFilepath = 'input.txt';
    outputFilepath = 'output.txt';
type
    Line = record
                a: Real;
                b: Real;
            end;
var
    df: text;
    i, j: integer;
    a, b, c, d, xp, yp: real;
    lines: array[1..maxLines] of Line;

begin
    {Reading lines}
    assign(df, inputFilepath);
    reset(df);
    i := 1;
    while not eof(df) do begin
        readln(df, a, b);
        lines[i].a := a;
        lines[i].b := b;
        inc(i);
    end;
    close(df);

    {Writing intersections}
    assign(df, outputFilepath);
    rewrite(df);
    for j:=2 to i-1 do begin
        a := lines[j-1].a;
        c := lines[j-1].b;
        b := lines[j].a;
        d := lines[j].b;

        if abs(a-b)<eps then
            writeln(df, 'parallels')
        else begin
            xp := (d-c)/(a-b);
            yp := a*xp+c;
            writeln(df, xp:0:3, ',', yp:0:3);
        end;
    end;
    close(df);
end.