#include <bits/stdc++.h>
using namespace std;
const int N = 1e6 + 10;
int n, m, z[N], pa[N], pb[N], f[N];
char a[N], b[N], s[N];
long long ans, f2[N], c1[N], c2[N];
void add(int x, int p) {
  for (; x < m; x += x & -x) f[x]++, f2[x] += p;
}
long long ask(int x) {
  int y = 0, z = x;
  long long y2 = 0;
  for (; x; x -= x & -x) y += f[x], y2 += f2[x];
  return 1ll * y * (z + 1) - y2;
}
void getz() {
  z[1] = n;
  for (int i = 2, l = 0, r = 0; i <= m; i++) {
    z[i] = i <= r ? min(z[i - l + 1], r - i + 1) : 0;
    while (s[i + z[i]] == s[1 + z[i]]) z[i]++;
    if (i + z[i] - 1 > r) r = i + z[i] - 1, l = i;
  }
}
void getp(int *p) {
  for (int i = 1, l = 0, r = 0; i <= n; i++) {
    p[i] = i <= r ? min(z[i - l + 1], r - i + 1) : 0;
    while (a[i + p[i]] == s[1 + p[i]]) p[i]++;
    if (i + p[i] - 1 > r) r = i + p[i] - 1, l = i;
  }
}
int main() {
  scanf("%d%d", &n, &m);
  scanf("%s%s%s", a + 1, b + 1, s + 1);
  a[n + 1] = 1;
  b[n + 1] = 2;
  s[m + 1] = 3;
  getz();
  getp(pa);
  reverse(b + 1, b + n + 1);
  reverse(s + 1, s + m + 1);
  memcpy(a, b, sizeof(b));
  getz();
  getp(pb);
  reverse(pb + 1, pb + n + 1);
  for (int i = 1; i <= n; i++) c1[pa[i]]++, c2[pb[i]]++;
  for (int i = n; i; i--) c1[i] += c1[i + 1], c2[i] += c2[i + 1];
  for (int i = 1; i <= min(n, m - 1); i++) ans += c1[i] * c2[m - i];
  for (int i = m; i <= n; i++) {
    if (pa[i - m + 1])
      add(max(m - pa[i - m + 1], 1), max(m - pa[i - m + 1], 1));
    ans -= ask(min(m - 1, pb[i]));
  }
  memset(f, 0, sizeof(f));
  memset(f2, 0, sizeof(f2));
  for (int i = 2; i <= n; i++) {
    if (pb[i - 1]) add(max(m - pb[i - 1], 1), max(m - pb[i - 1], 1));
    ans -= ask(min(m - 1, pa[i]));
  }
  cout << ans;
}
