时间限制：C/C++/Rust/Pascal 1秒，其他语言2秒
空间限制：C/C++/Rust/Pascal 32 M，其他语言64 M
64bit IO Format: %lld
空间限制：C/C++/Rust/Pascal 32 M，其他语言64 M
64bit IO Format: %lld
题目描述
Wisconsin has had an earthquake that has struck Farmer John's farm! The earthquake has damaged some of the pastures so that they are unpassable. Remarkably, none of the cowpaths was damaged.
As usual, the farm is modeled as a set of P (1 <= P <= 30,000) pastures conveniently numbered 1..P which are connected by a set of C (1 <= C <= 20,000) non-directional cowpaths conveniently numbered 1..C. Cowpath i connects pastures
and 
(1 <= <= P; 1 <= <= P). Cowpaths might connect to itself or perhaps might connect two pastures more than once. The barn is located in pasture 1.
A total of N (1 <= N <= P) cows (in different pastures) sequentially contact Farmer John via mobile phone with an integer message
(2 <= <= P) that indicates that pasture is undamaged but that the alling cow is unable to return to the barn from pasture because she could not find a ath that does not go through damaged pastures.
After all the cows report in, determine the minimum number of pastures that are damaged.
As usual, the farm is modeled as a set of P (1 <= P <= 30,000) pastures conveniently numbered 1..P which are connected by a set of C (1 <= C <= 20,000) non-directional cowpaths conveniently numbered 1..C. Cowpath i connects pastures
A total of N (1 <= N <= P) cows (in different pastures) sequentially contact Farmer John via mobile phone with an integer message
After all the cows report in, determine the minimum number of pastures that are damaged.
输入描述:
* Line 1: Three space-separated integers: P, C, and N
* Lines 2..C+1: Line i+1 describes cowpath i with two integers:
* Lines C+2..C+N+1: Line C+1+j contains a single integer:
输出描述:
* Line 1: A single integer that is the minimum count of pastures from which a cow can not return to the barn (including the damaged pastures themselves)