1) var
t, z: real;
begin
readln(t);
if (t > 2) then
z := 16 * t
else
z := t * t - 4;
writeln(z);
end.
2) var
x, v: real;
begin
readln(x);
if (x >= 5) then
v := sqrt(x - 5);
if (x >= -20) and (x < 5) then
v := abs(x - 15);
if (x < -20) then
v := x * x - 400;
writeln(v);
end.
3) var
x, v: real;
begin
readln(x);
if (x > 0) then
v := cos(x)
else
v := x * x - 1;
writeln(v);
end.