function f = del(x)
    Cost = 1100;
    Size = 3900;
    Power = 1.9;
    Time = 600;
    [N temp]= size(x);
    y = [];
    j = 1;
    for i = 1: N
        if (x(i, 1) <= Cost) & (x(i, 2) <= Size) & (x(i, 3) <= Power) & (x(i, 4) <= Time)
            y(j, :) = x(i, :);
            j = j + 1;
        end
    end
    f = y;