Program one;
var a,b,c:real;
begin
Readln(a,b,c);
writeln((b+sqrt(b*b+4*a*c))/2*a - a*a*a*c+1/(b*b))
end.
program two;
var a,b,c,d:real;
begin
Readln(a,b,c,d);
writeln((a/c)*(b/d)- (a*b-c)/(c*d))
end.
program three;
var x,y:real;
begin
Readln(x,y);
writeln((Sin(x)+cos(y))/(Cos(x)-sin(y))*tan(x*y))
end.
program four;
var x,y:real;
begin
Readln(x,y);
writeln((x+y)/(y+1)-((x*y)-12)/(34+x))
end.