PivotOJ

Cowntact Tracing

시간 제한: 2000ms메모리 제한: 1024MB출처: USACO 2023 December PlatinumBOJ 31054

문제

Farmer John has NN (2N1052\le N\le 10^5) cows labeled 1N1\dots N, where the connections between cows are described by a tree. Unfortunately, there is a sickness spreading throughout.

Initially, some cows start off infected. Every night, an infected cow spreads the sickness to their neighbors. Once a cow is infected, she stays infected. After some amount of nights, Farmer John realizes that there is an issue so he tests his cows to determine who has the sickness.

You are given QQ (1Q201\le Q\le 20) different values for the number of nights, each an integer in the range [0,N][0,N]. For each number of nights, determine the minimum number of cows that could have started with the illness, or that the number of nights is inconsistent with the given information.

입력

The first line contains NN.

The next line contains a bit string of length NN, where the iith bit is 1 if the iith cow is infected and 0 otherwise. At least one cow is infected.

The next N1N-1 lines contain the edges of the tree.

Then QQ, followed by the QQ values for the number of nights.

출력

QQ lines, the answers for each number of nights, or 1-1 if impossible.

예제

예제 1

입력
5
11111
1 2
2 3
3 4
4 5
6
5
4
3
2
1
0
출력
1
1
1
1
2
5

예제 2

입력
10
1111111111
1 2
2 3
2 4
2 5
2 6
6 7
7 8
8 9
9 10
11
0
1
2
3
4
5
6
7
8
9
10
출력
10
3
2
1
1
1
1
1
1
1
1

예제 3

입력
5
11100
1 2
2 3
3 4
4 5
6
0
1
2
3
4
5
출력
3
1
1
-1
-1
-1
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