program raf105;
var x,a,c,b: real;
begin
write('a = ');
readln(a);
write('b = ');
readln(b);
write('c = ');
readln(c);
x:= (abs(a)-3*c)/(b*b);
writeln('x = ',x);
end.
program raf105;
var x,a,c,b: real;
begin
write('a = ');
readln(a);
write('b = ');
readln(b);
write('c = ');
readln(c);
x:= (abs(a)-3*c)/(b*b);
writeln('x = ',x);
end.