var

 a, b, s: real;

begin

 a := 5;

 b := -3.5;

 s := a + b;

 s := 2 * s - b;

 write(s);

end.

var s,a,b:real;

begin

a:=5;

b:=-3.5;

s:=a+b;

s:=2*s-b;

writeln('s = ',s);

end.

program n_1;

var

 a: integer;

 b, s: real;

begin

 a := 5;

 b := -3.5;

 s := a + b;

 s := s * 2 - b;

 writeln(s)

end.