#1
var
x,y,z : integer;
a : real;
begin
readln(x,y,z);
a := ((x + y - z)/(x*x + 2));
writeln(a);
end.
#2
var
x,y,z : integer;
a : real;
begin
readln(x,y,z);
a := 5*((2*x-z)/(3+y*y));
writeln(a);
end.
#3
var
x,y,z : integer;
a : real;
begin
readln(x,y,z);
a := (1 + z)*((x+(y/x*x+4))/(2+(1/(x*x+4))));
writeln(a);
end.
#2.1
const pi = 3.14;
var
l,s,r : real;
begin
readln(r);
l := 2 * pi * r;
s := pi * r * r;
writeln(l);
writeln(s);
end.
#2.2
var
x : real;
begin
readln(x);
writeln((180 - x)/2);
end.