Peter, age $45,$ made his first Roth IRA contribution ten years ago and has made contributions to the IRA every year since. His total contributions amount to $$40,000,$ and he has never previously taken a distribution from the IRA. If he withdrew $$50,000$ this year from the Roth IRA in a nonqualified distribution, what is the maximum amount of the distribution, if any, he may exclude from income?