C. 650.

(5 points)

Deadline expired.

Statistics on problem C. 650. 376 students sent a solution. 5 points: 321 students. 4 points: 5 students. 3 points: 2 students. 2 points: 9 students. 1 point: 1 student. 0 point: 34 students. Unfair, not evaluated: 4 solutions.