1 /**************************************************************
 2     Problem: 1566
 3     User: rausen
 4     Language: Pascal
 5     Result: Accepted
 6     Time:11920 ms
 7     Memory:3592 kb
 8 ****************************************************************/
 9
10 const prime = 1024523;
11
12 var
13   s1, s2 : array[0..600] of char;
14   m, n, i, j, k, j1, k1 : longint;
15   p, q : longint;
16   f : array[0..1, 0..600, 0..600] of longint;
17
18 procedure reverse;
19 var
20   s : ansistring;
21   i : longint;
22
23 begin
24   readln(s);
25   for i := 1 to m do
26     s1[m - i + 1] := s[i];
27   readln(s);
28   for i := 1 to n do
29     s2[n - i + 1] := s[i];
30 end;
31
32 begin
33   readln(m, n);
34   reverse;
35   f[0, 1, 1] := 1;
36   for i := 1 to m + n + 1 do begin
37     p := i mod 2;
38     q := p xor 1;
39     fillchar(f[p], sizeof(f[p]), 0);
40     for j := 1 to m + 1 do
41       for k := 1 to m + 1 do
42         while f[q, j, k] >= prime do
43           dec(f[q, j, k], prime);
44     for j := 1 to m + 1 do
45       for k := 1 to m + 1 do begin
46         j1 := i - j + 1;
47         k1 := i - k + 1;
48         if (j1 > 0) and (k1 > 0) and (j1 <= n + 1) and (k1 <= n + 1) then begin
49           if s1[j] = s1[k] then inc(f[p, j + 1, k + 1], f[q, j, k]);
50           if s1[j] = s2[k1] then inc(f[p, j + 1, k], f[q, j ,k]);
51           if s2[j1] = s1[k] then inc(f[p, j, k + 1], f[q, j ,k]);
52           if s2[j1] = s2[k1] then inc(f[p, j, k], f[q, j, k]);
53         end;
54       end;
55   end;
56   writeln(f[q, m + 1, m + 1]);
57 end.