Program KVUR2;
Var a, b, c, d, x, x1, x2: real;
Begin
 writeln ('  ');
 write ('  a, b, c: ');
 readln (a, b, c); 
 d := b*b-4*a*c;
 if d<0 then
   writeln (' !')
 else
   if d=0 then
     begin
     writeln (' :');
     x:=-b/(2*a); writeln ('x=', x:5:1);
     end
   else   
     begin
     writeln (' :');
     x1:=(-b+sqrt(d))/(2*a); x2:=(-b-sqrt(d))/(2*a);
     writeln ('x1=', x1:5:1, ' x2=', x2:5:1)
     end;
End.