program m1;
var x,y,z,a,b,c: real;
begin
read(a,b,c);
x:=(a+b)/c;
y:=a+b+c;
z:=(power(sin(x*y+1), 2)/2 + (2*power(x*y, 0.5))/(1+x));
writeln(z);
end.
