#include <bits/stdc++.h>   using namespace std;   int a[200005], b[200005];   int nx[500005];   int n, m;   void getnext() {     nx[0] = -1;     int j = 0, k = -1;     while (j < m) {       if (k == -1 || b[j] == b[k])         nx[++j] = ++k;       else         k = nx[k];     }   }   int KMP() {     int ret = 0;     int i = 0, j = 0;     for (i = 0; i < n; i++) {       while (j > 0 && a[i] != b[j]) j = nx[j];       if (a[i] == b[j]) j++;       if (j == m) {         ret++;         j = nx[j];       }     }     return ret;   }   int main() {     ios::sync_with_stdio(false);     cin.tie(0);     cout.tie(0);     cin >> n >> m;     for (int i = 0; i < n; i++) {       cin >> a[i];       if (i != 0) a[i - 1] = a[i] - a[i - 1];     }     for (int i = 0; i < m; i++) {       cin >> b[i];       if (i != 0) b[i - 1] = b[i] - b[i - 1];     }     if (m == 1) {       cout << n << endl;       return 0;     }     n--;     m--;     getnext();     cout << KMP() << endl;     return 0;   }   