#include <bits/stdc++.h>
using namespace std;
const int MAXN = 200 * 1000 + 10, INF = INT_MAX, MOD = 1e9 + 7;
map<int, int> cnt1, cnt;
int a[MAXN], b[MAXN];
int main() {
  ios::sync_with_stdio(false);
  int n, m, p;
  cin >> n >> m >> p;
  for (int i = 0; i < n; i++) cin >> a[i];
  for (int i = 0; i < m; i++) {
    cin >> b[i];
    cnt[b[i]]++;
  }
  vector<int> ans;
  for (int i = 0; i < p; i++) {
    cnt1.clear();
    int t = m;
    for (int j = i, k = 0; j < n; j += p, k++) {
      cnt1[a[j]]++;
      if (cnt1[a[j]] <= cnt[a[j]]) t--;
      if (k >= m) {
        int idx = j - m * p;
        cnt1[a[idx]]--;
        int cur = max(0, cnt[a[idx]] - cnt1[a[idx]]);
        if (cur > 0) t++;
      }
      if (t == 0) ans.push_back(j - (m - 1) * p);
    }
  }
  cout << ((int)ans.size()) << endl;
  sort(ans.begin(), ans.end());
  for (__typeof((ans).begin()) i = (ans).begin(); i != (ans).end(); i++)
    cout << *i + 1 << ' ';
  return 0;
}
