#include <bits/stdc++.h>
using namespace std;
inline int read() {
  int x = 0;
  char ch = getchar();
  while (!isdigit(ch)) ch = getchar();
  while (isdigit(ch)) x = x * 10 + ch - '0', ch = getchar();
  return x;
}
int pos[200010];
unsigned long long Pow[200010];
struct SegmentTree {
  unsigned long long val[200010 << 2];
  int num[200010 << 2];
  inline void update(int k) {
    num[k] = num[k << 1] + num[k << 1 | 1];
    val[k] = val[k << 1] * Pow[num[k << 1 | 1]] + val[k << 1 | 1];
  }
  inline void change(int k, int l, int r, int p, int dat) {
    if (p < l || r < p) return;
    if (l == r) return (void)(val[k] = dat, num[k] = (dat != 0));
    change(k << 1, l, ((l + r) >> 1), p, dat),
        change(k << 1 | 1, ((l + r) >> 1) + 1, r, p, dat), update(k);
  }
} T;
int main() {
  int n = read(), m = read();
  unsigned long long H = 0, sum = 0;
  Pow[0] = 1;
  for (int i = 1; i <= n; i++) {
    int x = read();
    H = H * 23 + x;
    Pow[i] = Pow[i - 1] * 23;
    sum += Pow[i - 1];
  }
  int ans = 0;
  for (int i = 1; i <= m; i++) pos[read()] = i;
  for (int i = 1; i <= m; i++) {
    if (i > n) T.change(1, 1, m, pos[i - n], 0);
    T.change(1, 1, m, pos[i], i);
    if (i >= n && T.val[1] == 1ULL * (i - n) * sum + H) ++ans;
  }
  cout << ans << endl;
  return 0;
}
