Two Permutations

给出两个排列$a,b $，长度分别为 $n,m$，你需要计算有多少个$ x $， 使得 $a_1 + x,a_2 + x,...a_n + x$ 是 $b$ 的子序列 $n \leq m \leq 2 \times 10^5$

Rubik is very keen on number permutations. A permutation $ a $ with length $ n $ is a sequence, consisting of $ n $ different numbers from 1 to $ n $ . Element number $ i $ $ (1<=i<=n) $ of this permutation will be denoted as $ a_{i} $ . Furik decided to make a present to Rubik and came up with a new problem on permutations. Furik tells Rubik two number permutations: permutation $ a $ with length $ n $ and permutation $ b $ with length $ m $ . Rubik must give an answer to the problem: how many distinct integers $ d $ exist, such that sequence $ c $ $ (c_{1}=a_{1}+d,c_{2}=a_{2}+d,...,c_{n}=a_{n}+d) $ of length $ n $ is a subsequence of $ b $ . Sequence $ a $ is a subsequence of sequence $ b $ , if there are such indices $ i_{1},i_{2},...,i_{n} $ $ (1<=i_{1}&lt;i_{2}&lt;...&lt;i_{n}<=m) $ , that $ a_{1}=b_{i1} $ , $ a_{2}=b_{i2} $ , $ ... $ , $ a_{n}=b_{in} $ , where $ n $ is the length of sequence $ a $ , and $ m $ is the length of sequence $ b $ . You are given permutations $ a $ and $ b $ , help Rubik solve the given problem.

The first line contains two integers $ n $ and $ m $ $ (1<=n<=m<=200000) $ — the sizes of the given permutations. The second line contains $ n $ distinct integers — permutation $ a $ , the third line contains $ m $ distinct integers — permutation $ b $ . Numbers on the lines are separated by spaces.

On a single line print the answer to the problem.

1 1
1
1

1

1 2
1
2 1

2

3 3
2 3 1
1 2 3

0