Complete the following sentence: On 26 December 2016, Lalatović became manager of Čukarički, penning a four-year contract. ️<unk>️<unk>️<unk>️<unk>️<unk>️<unk>️<unk>️<unk>️<unk>️<unk>️<unk>️<unk>️<unk>️<unk>️<unk>️<unk>️<unk>️<unk>️<unk>️<unk>️<unk>️<unk>️<unk>️<unk>️<unk>️<unk>️ During his time at Čukarički, Lalatović also served as manager of the Serbia national under-21 team at the
2017 UEFA U-21 Championship.