#include <bits/stdc++.h>
using namespace std;
vector<int> exKmp(const char *s, int n) {
  vector<int> z(n, 0);
  z[0] = n;
  for (int i = 1, l = 0, r = 0; i < n; i++) {
    if (i <= r) z[i] = min(r - i + 1, z[i - l]);
    while (i + z[i] < n && s[i + z[i]] == s[z[i]]) z[i]++;
    if (i + z[i] - 1 > r) l = i, r = i + z[i] - 1;
  }
  return z;
}
const int maxn = 5e5 + 5;
char tp[maxn * 3];
vector<int> getInfo(char *t, int n, char *s, int m) {
  memcpy(tp, s, sizeof(char) * (m - 1));
  tp[m - 1] = 0;
  memcpy(tp + m, t, sizeof(char) * n);
  vector<int> z = exKmp(tp, n + m);
  vector<int> ans(n);
  memcpy(&ans[0], (&z[m]), sizeof(int) * n);
  return ans;
}
template <typename T>
void reverse(T *p, int n) {
  for (int i = 0; i * 2 < n; i++) {
    swap(p[i], p[n - i - 1]);
  }
}
long long bit[2][maxn * 2];
inline int lowbit(int x) { return x & (-x); }
int n, m;
void add(int x, int v, long long *bit) {
  for (int i = x; i <= m; i += lowbit(i)) bit[i] += v;
}
long long get(int x, long long *bit) {
  long long ans = 0;
  for (int i = x; i; i -= lowbit(i)) ans += bit[i];
  return ans;
}
char sa[maxn], sb[maxn], c[maxn * 2];
int main() {
  scanf("%d%d", &n, &m);
  scanf("%s%s", sa, sb);
  scanf("%s", c);
  vector<int> a = getInfo(sa, n, c, m);
  reverse<char>(sb, n);
  reverse<char>(c, m);
  vector<int> b = getInfo(sb, n, c, m);
  reverse<int>(&b[0], b.size());
  long long ans = 0;
  for (int i = 0, j = 0; i < n; i++) {
    while (j <= i + m - 2 && j < n) {
      add(m - b[j], 1, bit[0]);
      add(m - b[j], b[j], bit[1]);
      j++;
    }
    ans += get(a[i], bit[0]) * (long long)(a[i] + 1 - m) + get(a[i], bit[1]);
    add(m - b[i], -1, bit[0]);
    add(m - b[i], -b[i], bit[1]);
  }
  printf("%lld\n", ans);
}
