#include <bits/stdc++.h>
using namespace std;
template <typename T>
T BigMod(T b, T p, T m) {
  if (p == 0) return 1;
  if (p % 2 == 0) {
    T s = BigMod(b, p / 2, m);
    return ((s % m) * (s % m)) % m;
  }
  return ((b % m) * (BigMod(b, p - 1, m) % m)) % m;
}
template <typename T>
T ModInv(T b, T m) {
  return BigMod(b, m - 2, m);
}
template <typename T>
T in() {
  char ch;
  T n = 0;
  bool ng = false;
  while (1) {
    ch = getchar();
    if (ch == '-') {
      ng = true;
      ch = getchar();
      break;
    }
    if (ch >= '0' && ch <= '9') break;
  }
  while (1) {
    n = n * 10 + (ch - '0');
    ch = getchar();
    if (ch < '0' || ch > '9') break;
  }
  return (ng ? -n : n);
}
template <typename T>
T POW(T B, T printf) {
  if (printf == 0) return 1;
  if (printf & 1)
    return B * POW(B, printf - 1);
  else
    return (POW(B, printf / 2) * POW(B, printf / 2));
}
template <typename T>
T Bigmod(T b, T p, T m) {
  if (p == 0)
    return 1;
  else if (!(p & 1))
    return (Bigmod(b, p / 2, m) * Bigmod(b, p / 2, m)) % m;
  else
    return ((b % m) * Bigmod(b, p - 1, m)) % m;
}
template <typename T>
T Dis(T x1, T y1, T x2, T y2) {
  return sqrt((x1 - x2 * x1 - x2) + (y1 - y2 * y1 - y2));
}
template <typename T>
T Angle(T x1, T y1, T x2, T y2) {
  return atan(double(y1 - y2) / double(x1 - x2));
}
template <typename T>
T DIFF(T a, T b) {
  T d = a - b;
  if (d < 0)
    return -d;
  else
    return d;
}
template <typename T>
T ABS(T a) {
  if (a < 0)
    return -a;
  else
    return a;
}
template <typename T>
T gcd(T a, T b) {
  if (a < 0) return gcd(-a, b);
  if (b < 0) return gcd(a, -b);
  return (b == 0) ? a : gcd(b, a % b);
}
template <typename T>
T lcm(T a, T b) {
  if (a < 0) return lcm(-a, b);
  if (b < 0) return lcm(a, -b);
  return a * (b / gcd(a, b));
}
template <typename T>
T euclide(T a, T b, T &x, T &y) {
  if (a < 0) {
    T d = euclide(-a, b, x, y);
    x = -x;
    return d;
  }
  if (b < 0) {
    T d = euclide(a, -b, x, y);
    y = -y;
    return d;
  }
  if (b == 0) {
    x = 1;
    y = 0;
    return a;
  } else {
    T d = euclide(b, a % b, x, y);
    T t = x;
    x = y;
    y = t - (a / b) * y;
    return d;
  }
}
template <typename T>
void ia(T a[], int n) {
  for (int i = 0; i < n; i++) cin >> a[i];
}
template <typename T>
void pa(T a[], int n) {
  for (int i = 0; i < n - 1; i++) cout << a[i] << " ";
  cout << a[n - 1] << endl;
}
template <typename T>
long long int isLeft(T a, T b, T c) {
  return (a.x - b.x) * (b.y - c.y) - (b.x - c.x) * (a.y - b.y);
}
int Set(int N, int pos) { return N = N | (1 << pos); }
int Reset(int N, int pos) { return N = N & ~(1 << pos); }
bool Check(int N, int pos) { return (bool)(N & (1 << pos)); }
template <class T, class first>
inline T togglebit(T a, first i) {
  T t = 1;
  return (a ^ (t << i));
}
int toInt(string s) {
  int sm;
  stringstream ss(s);
  ss >> sm;
  return sm;
}
int toLlint(string s) {
  long long int sm;
  stringstream ss(s);
  ss >> sm;
  return sm;
}
int cdigittoint(char ch) { return ch - '0'; }
bool isVowel(char ch) {
  ch = toupper(ch);
  if (ch == 'A' || ch == 'U' || ch == 'I' || ch == 'O' || ch == 'E')
    return true;
  return false;
}
bool isConst(char ch) {
  if (isalpha(ch) && !isVowel(ch)) return true;
  return false;
}
double DEG(double x) { return (180.0 * x) / (2.0 * acos(0.0)); }
double RAD(double x) { return (x * (double)2.0 * acos(0.0)) / (180.0); }
pair<unsigned long long int, unsigned long long int> H[26][200007];
pair<unsigned long long int, unsigned long long int> F[26];
int nxt[26][200007];
bool a[2][26][200007];
unsigned long long int B1[200007], B2[200007];
char s[200007], t[200007];
bool vis[28];
int ans[200007], L;
int par[200007];
void Init() {
  B1[0] = B2[0] = 1;
  for (int i = 1; i < 200007; i++) {
    B1[i] = B1[i - 1] * 10000019ULL;
    B2[i] = B2[i - 1] * 10000079ULL;
  }
}
pair<unsigned long long int, unsigned long long int> SubStr(int f, int l,
                                                            int r) {
  int len = r - l + 1;
  pair<unsigned long long int, unsigned long long int> ans;
  ans.first = H[f][r].first - H[f][l - 1].first * B1[len];
  ans.second = H[f][r].second - H[f][l - 1].second * B2[len];
  return ans;
}
int FindPar(int n) {
  if (par[n] == n)
    return n;
  else
    return par[n] = FindPar(par[n]);
}
int main() {
  Init();
  int n, m;
  scanf("%d%d", &n, &m);
  scanf("%s%s", s + 1, t + 1);
  for (int i = 1; i <= n; i++) a[0][s[i] - 'a'][i] = 1;
  for (int i = 1; i <= m; i++) a[1][t[i] - 'a'][i] = 1;
  for (int i = 0; i < 26; i++) {
    for (int j = 1; j <= n; j++) {
      H[i][j].first = H[i][j - 1].first * 10000019ULL + (a[0][i][j]) + 1;
      H[i][j].second = H[i][j - 1].second * 10000079ULL + (a[0][i][j]) + 1;
    }
    nxt[i][n + 1] = n + 1;
    for (int j = n; j; j--) {
      if (a[0][i][j])
        nxt[i][j] = j;
      else
        nxt[i][j] = nxt[i][j + 1];
    }
  }
  for (int i = 0; i < 26; i++) {
    for (int j = 1; j <= m; j++) {
      F[i].first = F[i].first * 10000019ULL + (a[1][i][j]) + 1;
      F[i].second = F[i].second * 10000079ULL + (a[1][i][j]) + 1;
    }
  }
  for (int i = 1; i <= n - m + 1; i++) {
    for (int j = 0; j <= 26; j++) vis[j] = 0;
    for (int j = 0; j < 26; j++) {
      if (vis[j]) continue;
      int pos = nxt[j][i];
      if (pos > i + m - 1) {
        vis[j] = 1;
        continue;
      }
      int dif = s[pos] - t[1 + (pos - i)];
      pair<unsigned long long int, unsigned long long int> xx =
          SubStr(j, i, i + m - 1);
      pair<unsigned long long int, unsigned long long int> yy =
          SubStr(j - dif, i, i + m - 1);
      if (xx == F[j - dif] && yy == F[j]) {
        vis[j] = vis[j - dif] = 1;
      }
    }
    int cnt = 0;
    for (int j = 0; j < 26; j++) cnt += vis[j];
    if (cnt == 26) ans[++L] = i;
  }
  printf("%d\n", L);
  for (int i = 1; i <= L; i++) printf("%d%c", ans[i], i == L ? '\n' : ' ');
  return 0;
}
