## finding an unbiased estimatior

today my friend shot me with a question but sadly i couldn't solve it. Here is the question:

let $X_1$ and $X_2$ be two iid random variables which follow Bernoulli distribution with $p$. But $p$ is such that it lies between $1/3$ and $2/3$. What will be an unbiased estimator for $p$ now.