var X : array [0..5]of real = (-3.2, 3.33, -2.8, 2.95, -3.01, 0);
    Y : array [0..4] of real = (5.1, -4.8, 4.99, -5.01, 5.4);
    Z : array [0..3] of real = (-1.44, -1.5, 1.80, -1.77);
    sr_arif1, sr_arif2, sr_arif3, min : real;

function sr_arif ( a : array of real; n : integer ) : real;
var i : integer;
    sum, cnt : real;
begin
    cnt := 0;
    sum := 0;
    for i := 0 to n - 1 do
    begin
        if a[i] < 0 then
        begin
            cnt := cnt + 1;
            sum := sum + a[i];
        end;
    end;
    sr_arif := sum / cnt;
end;

begin
    sr_arif1 := sr_arif(X, 6);
    sr_arif2 := sr_arif(Y, 5);
    sr_arif3 := sr_arif(Z, 4);
    min := sr_arif1;
    if sr_arif2 < min then
    begin
        min := sr_arif2;
    end;
    if sr_arif3 < min then
    begin
        min := sr_arif3;
    end;
    writeln(sr_arif1);
    writeln(sr_arif2);
    writeln(sr_arif3);
    writeln(min);
end.