#include <bits/stdc++.h>
using namespace std;
int main() {
  long long m = 100000, n = 0, a[1005], b[1005], u, i, j, k = 0, c, d, s = 0,
            r = 0;
  char str1[1005], str2[1005];
  cin >> c >> d;
  scanf("%s", str1);
  scanf("%s", str2);
  for (i = 0, j = 0;; i++, j++) {
    if (str1[i] != str2[j]) {
      k++;
      a[n] = i + 1;
      n++;
    }
    if (i == c - 1) {
      i = -1;
      s++;
      j = -1;
      j += s;
      if (k < m) {
        m = k;
        for (r = 0; r < k; r++) {
          b[r] = a[r];
        }
      }
      r = 0;
      k = 0;
      n = 0;
      if (s == (d - c + 1)) break;
    }
  }
  cout << m << endl;
  for (u = 0; u < m; u++) cout << b[u] << " ";
}
