Program abc;
var a,b,c:integer; s,k,y:real;
begin
readln(a);
readln(b);
readln(c);
s:=(sqrt(2*a+3*b*b*b))/(a-c);
k:=(2*s*s*s*s)-(3*sqrt(abs(a*b*c)));
y:=(6*s+2*k)-((s*s*s*s)/(3*a*b*c));
writeln(y);
end.
Program abc;
var a,b,c:integer; s,k,y:real;
begin
readln(a);
readln(b);
readln(c);
s:=(sqrt(2*a+3*b*b*b))/(a-c);
k:=(2*s*s*s*s)-(3*sqrt(abs(a*b*c)));
y:=(6*s+2*k)-((s*s*s*s)/(3*a*b*c));
writeln(y);
end.