P2996 [USACO10NOV] Visiting Cows G

After many weeks of hard work, Bessie is finally getting a vacation! After many weeks of hard work, Bessie is finally getting a vacation! numbered 1..N. The cows have set up quite an unusual road network with exactly N-1 roads connecting pairs of cows C1 and C2 (1

\* Line 1: A single integer: N \* Lines 2..N: Each line describes a single road with two space-separated integers: C1 and C2

\* Line 1: A single integer representing the maximum number of cows that Bessie can visit.

Bessie knows 7 cows. Cows 6 and 2 are directly connected by a road, as are cows 3 and 4, cows 2 and 3, etc. The illustration below depicts the roads that connect the cows: 1--2--3--4 | 5--6--7 Bessie can visit four cows. The best combinations include two cows on the top row and two on the bottom. She can't visit cow 6 since that would preclude visiting cows 5 and 7; thus she visits 5 and 7. She can also visit two cows on the top row: {1,3}, {1,4}, or {2,4}.