We prove that every $n$-vertex directed graph $G$ with the minimum outdegree $δ^+(G) = d$ contains a subgraph $H$ satisfying \[ \min\left\{δ^+(H), δ^-(H) \right\} \ge \frac{d(d+1)}{2n} \,.\] We also show that if $d = o(n)$ then this bound is asymptotically best possible.
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