1 #include<bits/stdc++.h>
 2 using namespace std;
 3 const int N=200005;
 4 
 5 int aa[N],a[N];
 6 int bb[N],b[N];
 7 int n,m;
 8 int Next[N];
 9 
10 void getnext()
11 {
12     int j, k;
13     j = 0; k = -1; Next[0] = -1;
14     while(j < m)
15         if(k == -1 || b[j] == b[k])
16             Next[++j] = ++k;
17         else
18             k = Next[k];
19 
20 }
21 
22 int KMP_Count()
23 {
24     int ans = 0;
25     int i, j = 0;
26 
27     if(n == 1 && m == 1)
28     {
29         if(a[0] == b[0])
30             return 1;
31         else
32             return 0;
33     }
34     getnext();
35     for(i = 0; i < n; i++)
36     {
37         while(j > 0 && a[i] != b[j])
38             j = Next[j];
39         if(a[i] == b[j])
40             j++;
41         if(j == m)
42         {
43             ans++;
44             j = Next[j];
45         }
46     }
47     return ans;
48 }
49 
50 int main(){
51     scanf("%d%d",&n,&m);
52     for(int i=0;i<n;i++) scanf("%d",&aa[i]);
53     for(int i=0;i<m;i++) scanf("%d",&bb[i]);
54     for(int i=0;i<n-1;i++) a[i]=aa[i+1]-aa[i];
55     for(int i=0;i<m-1;i++) b[i]=bb[i+1]-bb[i];
56     n--;m--;
57     if(m==0){
58         cout<<n+1<<endl;return 0;
59     }
60     cout<<KMP_Count()<<endl;
61 }