#include <bits/stdc++.h>   using namespace std;   int m, n;   long long mas[300007];   long long ex[300007];   vector<long long> s;   int main() {     scanf( %d %d , &m, &n);     for (int i = 0; i < m; i++) {       scanf( %I64d , &mas[i]);     }     for (int i = 0; i < n; i++) {       scanf( %I64d , &ex[i]);     }     n--;     m--;     for (int i = 0; i < n; i++) {       ex[i] = ex[i + 1] - ex[i];       s.push_back(ex[i]);     }     s.push_back((long long)1000000000000);     for (int i = 0; i < m; i++) {       mas[i] = mas[i + 1] - mas[i];       s.push_back(mas[i]);     }     m = n + m + 1;     vector<int> z(m);     for (int i = 1, l = 0, r = 0; i < m; ++i) {       if (i <= r) z[i] = min(r - i + 1, z[i - l]);       while (i + z[i] < m && s[z[i]] == s[i + z[i]]) ++z[i];       if (i + z[i] - 1 > r) l = i, r = i + z[i] - 1;     }     int c = 0;     for (int i = n; i < m; i++)       if (z[i] >= n) c++;     cout << c;   }   