#include <bits/stdc++.h>
using namespace std;
long long n, d, m, p, t, ans;
vector<int> a, b;
map<int, int> ma, ma1;
int main() {
  cin >> n >> m >> p;
  a.resize(n);
  for (int i = 0; i < n; i++) {
    scanf("%d", &a[i]);
  }
  map<int, int>::iterator it;
  for (int i = 0; i < m; i++) {
    scanf("%d", &t);
    if (ma.find(t) == ma.end())
      ma[t] = -1;
    else
      ma[t]--;
  }
  if (1ll + (m - 1) * p > n) {
    printf("%d", 0);
    return 0;
  }
  ma1 = ma;
  int r = m;
  for (int i = 0; i < p; i++) {
    for (int j = i, k = 1; j < n; j += p, k++) {
      if (ma.find(a[j]) != ma.end()) {
        if (++ma[a[j]] < 1) r--;
      }
      if (k >= m) {
        if (k > m && ma.find(a[j - m * p]) != ma.end()) {
          if (--ma[a[j - m * p]] < 0) r++;
        }
        if (r == 0) b.push_back(j - (m - 1) * p);
      }
    }
    for (it = ma1.begin(); it != ma1.end(); it++) ma[it->first] = it->second;
    r = m;
  }
  cout << b.size() << endl;
  sort(b.begin(), b.end());
  for (int i = 0; i < b.size(); i++) {
    cout << b[i] + 1 << " ";
  }
  return 0;
}
