#include <bits/stdc++.h>
using namespace std;
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
#include <ext/pb_ds/detail/standard_policies.hpp>
using namespace __gnu_pbds;
typedef long long ll;
typedef pair<ll, ll> pll;
#define all(x) (x).begin(),(x).end()
#define X first
#define Y second
#define sep ' '
#define endl '\n'
#define debug(x) cerr << #x << ": " << x << endl;
#define ordered_set tree<int, null_type,less<int>, rb_tree_tag,tree_order_statistics_node_update>
const ll MAXN = 1e6 + 10;
const ll MOD = 1e9 + 7;
const ll p = 2;
inline ll poww(ll a, ll b) {
ll ans = 1;
while (b) {
if (b & 1) ans = ans * a % MOD;
a = a * a % MOD;
b >>= 1;
}
return ans;
}
ll sg[MAXN << 2], lz[MAXN << 2], H[MAXN], n, m, t_hsh, hsh,
p_pow[MAXN], B[MAXN], inv, ind[MAXN];
ordered_set st;
void Push(int v) {
sg[v] = sg[v] * lz[v] % MOD;
if ((v << 1 | 1) < (MAXN << 2)) {
lz[v << 1] = (lz[v << 1] * lz[v]) % MOD;
lz[v << 1 | 1] = (lz[v << 1 | 1] * lz[v]) % MOD;
}
lz[v] = 1;
}
ll Query(int QL, int QR = MAXN - 1, int L = 1, int R = MAXN - 1, int v = 1) {
Push(v);
if (QL > QR) return 0;
if (QL == L && QR == R) return sg[v];
int mid = (L + R) >> 1;
return (Query(QL, min(QR, mid), L, mid, v << 1) +
Query(max(QL, mid + 1), QR, mid + 1, R, v << 1 | 1)) % MOD;
}
void Reset(int ind, ll val, int L = 1, int R = MAXN - 1, int v = 1) {
Push(v);
if (L == R) {
sg[v] = val;
return;
}
int mid = (L + R) >> 1;
if (ind <= mid) Reset(ind, val, L, mid, v << 1);
else Reset(ind, val, mid + 1, R, v << 1 | 1);
Push(v << 1);
Push(v << 1 | 1);
sg[v] = (sg[v << 1] + sg[v << 1 | 1]) % MOD;
}
inline void Divide() {
lz[1] = lz[1] * inv % MOD;
}
int main() {
ios_base::sync_with_stdio(false); cin.tie(0); cout.tie(0);
p_pow[0] = 1;
for (int i = 1; i < MAXN; i++)
p_pow[i] = p_pow[i - 1] * p % MOD;
for (int i = 1; i < (MAXN << 2); i++)
lz[i] = 1;
inv = poww(p, MOD - 2);
cin >> n >> m;
for (int i = 0; i < n; i++) {
ll x;
cin >> x;
ind[x] = i;
}
for (int i = 0; i < n; i++) {
t_hsh = (t_hsh + p_pow[i] * (ind[i + 1] + 1)) % MOD;
}
int ans = 0;
for (int i = 0; i < m; i++) {
cin >> B[i];
if (i >= n) {
ll ind = st.order_of_key(B[i - n]) + 1;
hsh = (hsh - ind + MOD) % MOD; // remove first element
hsh = hsh * inv % MOD; // div by p
Divide(); // div seg by p
hsh = (hsh - Query(B[i - n] + 1) + MOD) % MOD; // dec ind
st.erase(st.lower_bound(B[i - n]));
Reset(B[i - n], 0);
}
ll pw = p_pow[min(1ll * i, n - 1)], ind = st.order_of_key(B[i]) + 1;
st.insert(B[i]);
hsh = (hsh + Query(B[i])) % MOD; // inc ind
hsh = (hsh + pw * ind) % MOD; // add last element
Reset(B[i], pw);
if (i >= n - 1 && hsh == t_hsh) {
ans++;
}
}
cout << ans << endl;
return 0;
}
