#include <bits/stdc++.h>
const int MN = 500005;
void Z(char *str, int N, int *z) {
  z[1] = N;
  for (int i = 2; i <= N; ++i) z[i] = 0;
  for (int i = 2, l = 0, r = 0; i <= N; ++i) {
    if (i <= r) z[i] = std::min(z[i - l + 1], r - i + 1);
    while (i + z[i] <= N && str[i + z[i]] == str[1 + z[i]]) ++z[i];
    if (i + z[i] - 1 > r) l = i, r = i + z[i] - 1;
  }
}
int N, M, W;
char S1[MN], S2[MN], T1[MN * 2], T2[MN * 2];
char Str[MN * 3];
int z[MN * 3], Zlcp[MN], Zlcs[MN];
long long b1[MN * 2], b2[MN * 2];
inline void Add(long long *b, int i, long long x) {
  for (; i <= M; i += i & -i) b[i] += x;
}
inline long long Qur(long long *b, int i) {
  long long a = 0;
  for (; i; i -= i & -i) a += b[i];
  return a;
}
inline void Mdf(int p, int t) {
  int lcp = std::min(M - 1, Zlcp[p]);
  Add(b1, M - lcp, t), Add(b2, M - lcp, t * lcp);
}
inline long long Qur(int i) {
  return Qur(b2, M - i) - (i - 1) * Qur(b1, M - i);
}
long long Ans;
int main() {
  scanf("%d%d%s%s%s", &N, &M, S1 + 1, S2 + 1, T1 + 1);
  for (int i = 1; i <= M; ++i) T2[i] = T1[M - i + 1];
  std::reverse(S2 + 1, S2 + N + 1);
  for (int i = 1; i <= M; ++i) Str[i] = T1[i];
  Str[M + 1] = 'A';
  for (int i = 1; i <= N; ++i) Str[M + 1 + i] = S1[i];
  Z(Str, M + 1 + N, z);
  for (int i = 1; i <= N; ++i) Zlcp[i] = z[M + 1 + i];
  for (int i = 1; i <= M; ++i) Str[i] = T2[i];
  Str[M + 1] = 'A';
  for (int i = 1; i <= N; ++i) Str[M + 1 + i] = S2[i];
  Z(Str, M + 1 + N, z);
  for (int i = 1; i <= N; ++i) Zlcs[i] = z[M + 1 + N - i + 1];
  for (int i = 1; i <= N; ++i) {
    Mdf(i, 1);
    if (i >= M) Mdf(i - M + 1, -1);
    int lcs = std::min(M - 1, Zlcs[i]);
    if (!lcs) continue;
    Ans += Qur(M - lcs);
  }
  printf("%lld\n", Ans);
  return 0;
}
