const n = 20;
var a: array[1..n] of real;
i: integer;
begin
for i := 1 to n do
read(a[i]);
for i := 1 to n do
if(i mod 3 <> 0) then write(a[i], ' ');
end.
const n = 18;
var a: array[1..n] of integer;
i, max, fir: integer;
begin
max := 1;
fir := 0;
for i := 1 to n do
begin
read(a[i]);
if(fir = 0) and (a[i] > 0) then fir := i;
if(a [i] < 0) and (a[max] < a[i]) then max := i;
end;
i := a[max];
a[max] := a[fir];
a[fir] := i;
for i := 1 to n do
write(a[i], ' ');
end.