String Search (Also for Core/Database Engineering)

Delete characters of source one by one following order, a permutation of 1-based original indices; original indices are not renumbered after deletions. target is initially guaranteed to be a subsequence of source. Find the maximum number of leading deletions that can be performed consecutively while target remains a subsequence.

输入格式

The first two lines contain source and target (words without whitespace characters), and the last line contains a 1-based permutation of indices whose length equals the length of source. 1≤|source|≤100000, 1≤|target|≤|source|. Letter case is not arbitrarily restricted, and comparisons are case-sensitive.

输出格式

Output the single integer required by the problem.

样例 1

输入：

abbabaa
bb
7 1 2 5 4 3 6

输出：

3

样例 2

输入：

hkbdi
kd
1 4 2 3 5

输出：

1

样例 3

输入：

AaA
A
1 3 2

输出：

1

样例说明

The answers to the three public examples are, in order: 3; 1; 1. The examples were rechecked by independent enumeration, state search, or direct simulation.