#include <bits/stdc++.h>
using namespace std;
void solve(const string& pattern, const string& target, int p, int t) {
  if (p > t) return;
  int result = INT_MAX;
  int ind_at_max = -1;
  for (int i = 0; i <= t - p; i++) {
    int counter_diff = 0;
    for (int j = 0; j < p; j++) {
      if (pattern[j] != target[i + j] && pattern[j] != '?') counter_diff++;
    }
    if (counter_diff < result) {
      result = counter_diff;
      ind_at_max = i;
    }
  }
  cout << result << "\n";
  for (int j = 0; j < p; j++) {
    if (pattern[j] != target[ind_at_max + j] && pattern[j] != '?') {
      cout << j + 1 << " ";
    }
  }
  cout << "\n";
}
int main() {
  ios::sync_with_stdio(false);
  int p, t;
  string pattern, target;
  cin >> p >> t;
  cin >> pattern >> target;
  solve(pattern, target, p, t);
  return 0;
}
