#include <bits/stdc++.h>
using namespace std;
struct BIT {
  long long tree[2000005];
  BIT() { memset(tree, 0, sizeof(tree)); }
  inline long long lowbit(long long x) { return x & (-x); }
  inline void add(long long pos, long long val) {
    while (pos <= 2000000) tree[pos] += val, pos += lowbit(pos);
    return;
  }
  inline long long query(long long pos) {
    long long ans = 0;
    while (pos) ans += tree[pos], pos -= lowbit(pos);
    return ans;
  }
} bit1, bit2;
long long n, m, ans;
char a[2000005], b[2000005], c[2000005];
long long z[2000005], lcp[2000005], lcs[2000005];
inline void GetZ() {
  long long l = 0, r = 0;
  z[1] = m - 1;
  for (long long i = 2; i <= m; i++) {
    if (i <= r) z[i] = min(z[i - l + 1], r - i + 1);
    while (i + z[i] < m && c[i + z[i]] == c[z[i] + 1]) z[i]++;
    if (i + z[i] - 1 > r) l = i, r = i + z[i] - 1;
  }
  return;
}
inline void GetLCP() {
  long long l = 0, r = 0;
  for (long long i = 1; i <= n; i++) {
    if (i <= r) lcp[i] = min(z[i - l + 1], r - i + 1);
    while (i + lcp[i] <= n && lcp[i] + 1 < m && a[i + lcp[i]] == c[lcp[i] + 1])
      lcp[i]++;
    if (i + lcp[i] - 1 > r) l = i, r = i + lcp[i] - 1;
  }
  return;
}
inline void GetLCS() {
  long long l = 0, r = 0;
  for (long long i = 1; i <= n; i++) {
    if (i <= r) lcs[i] = min(z[i - l + 1], r - i + 1);
    while (i + lcs[i] <= n && lcs[i] + 1 < m && b[i + lcs[i]] == c[lcs[i] + 1])
      lcs[i]++;
    if (i + lcs[i] - 1 > r) l = i, r = i + lcs[i] - 1;
  }
  for (long long i = 1; i <= n / 2; i++) swap(lcs[i], lcs[n - i + 1]);
  return;
}
inline void add(long long len) {
  if (len != 0) {
    bit1.add(len, 1);
    bit2.add(len, len);
  }
  return;
}
inline void del(long long len) {
  if (len != 0) {
    bit1.add(len, -1);
    bit2.add(len, -len);
  }
  return;
}
inline long long query(long long x) {
  return (bit2.query(m - 1) - bit2.query(x)) -
         x * (bit1.query(m - 1) - bit1.query(x));
}
signed main() {
  cin >> n >> m;
  scanf("%s%s%s", a + 1, b + 1, c + 1);
  GetZ();
  GetLCP();
  for (long long i = 1; i <= m / 2; i++) swap(c[i], c[m - i + 1]);
  for (long long i = 1; i <= n / 2; i++) swap(b[i], b[n - i + 1]);
  memset(z, 0, sizeof(z));
  GetZ();
  GetLCS();
  long long j = 1;
  for (long long i = 1; i <= n; i++) {
    while (j <= i + m - 2 && j <= n) add(lcs[j]), j++;
    ans += query(m - lcp[i] - 1);
    del(lcs[i]);
  }
  cout << ans << endl;
  return 0;
}
