program TriangleType;
var
  a, b, c: integer;
begin
  write('Enter three sides of a triangle: ');
  readln(a, b, c);
  if (a + b <= c) or (a + c <= b) or (b + c <= a) then
    writeln('Invalid triangle')
  else
  begin
    if (a = b) and (b = c) then
      writeln('Equilateral triangle')
    else if (a = b) or (b = c) or (c = a) then
    begin
      if (sqr(a) + sqr(b) = sqr(c)) or (sqr(b) + sqr(c) = sqr(a)) or (sqr(c) + sqr(a) = sqr(b)) then
        writeln('Isosceles right triangle')
      else
        writeln('Isosceles triangle');
    end
    else if (sqr(a) + sqr(b) = sqr(c)) or (sqr(b) + sqr(c) = sqr(a)) or (sqr(c) + sqr(a) = sqr(b)) then
      writeln('Right triangle')
    else
      writeln('Scalene triangle');
  end;
end.