//1.63

Begin
  var y, a, x, b: double;
  
  write('Vvedite a: '); 
  readln(a);
  
  write('Vvedite b: ');
  readln(b);
  
  write('Vvedite x: ');
  readln(x);
  
  if (a < x)AND(x < b) then
    y := a + b * x * x * x
  else
    if x <= a then
      y := a - sin(a - sqrt(x))
    else
      y := ln(x-b) / ln(10);
      
  writeln('Y = ', y);
end.