#include <bits/stdc++.h>
using namespace std;
inline long long read() {
  long long x = 0, f = 1;
  char c = getchar();
  while (c < '0' || c > '9') {
    if (c == '-') f = -1;
    c = getchar();
  }
  while (c >= '0' && c <= '9') {
    x = (x << 1) + (x << 3) + c - '0';
    c = getchar();
  }
  return x * f;
}
int n, m;
int f[1000050], g[1000050];
char a[1000050], b[1000050], s[1000050];
long long ans;
struct BIT {
  long long b[1000050];
  inline int lowbit(int x) { return x & (-x); }
  inline long long Ask(int x) {
    long long ans = 0;
    while (x <= m) ans += b[x], x += lowbit(x);
    return ans;
  }
  inline void Add(int x, int d) {
    while (x) b[x] += d, x -= lowbit(x);
  }
} B0, B1;
int z[1000050];
void Z(char *s, int n) {
  z[1] = n;
  for (int i = 2, l = 0, r = 0; i <= n; ++i) {
    z[i] = 0;
    if (i <= r) z[i] = min(r - i + 1, z[i - l + 1]);
    while (i + z[i] <= n && s[i + z[i]] == s[z[i] + 1]) ++z[i];
    if (i + z[i] - 1 > r) l = i, r = i + z[i] - 1;
  }
}
void exkmp(char *s, char *t, int n, int m, int *p) {
  Z(t, m);
  for (int i = 1, l = 0, r = 0; i <= n; ++i) {
    if (i <= r) p[i] = min(r - i + 1, z[i - l + 1]);
    while (i + p[i] <= n && p[i] + 1 <= m && s[i + p[i]] == t[p[i] + 1]) ++p[i];
    if (i + p[i] - 1 > r) l = i, r = i + p[i] - 1;
  }
}
int main() {
  n = read(), m = read();
  scanf("%s", a + 1);
  scanf("%s", b + 1);
  scanf("%s", s + 1);
  exkmp(a, s, n, m, f);
  reverse(b + 1, b + n + 1);
  reverse(s + 1, s + m + 1);
  exkmp(b, s, n, m, g);
  reverse(g + 1, g + n + 1);
  for (int i = 1; i <= n; ++i) f[i] = min(f[i], m - 1), g[i] = min(g[i], m - 1);
  for (int i = 1; i <= min(n, m - 1); ++i) {
    B0.Add(g[i], 1);
    B1.Add(g[i], g[i]);
  }
  for (int i = 1; i <= n; ++i) {
    ans += B1.Ask(m - f[i]) + 1LL * B0.Ask(m - f[i]) * (f[i] - m + 1);
    B0.Add(g[i], -1);
    B1.Add(g[i], -g[i]);
    if (i + m - 1 <= n) {
      B0.Add(g[i + m - 1], 1);
      B1.Add(g[i + m - 1], g[i + m - 1]);
    }
  }
  printf("%lld\n", ans);
  return 0;
}
