function fibonacci(position: number): number {
  if (position === 0 || position === 1) return position;

  let prev = 0;
  let current = 1;

  for (let i = 2; i <= position; i++) {
    let next = prev + current;
    prev = current;
    current = next;
  }

  return current;
}

// No modificar: necesario para evaluar el resultado.
export { fibonacci };