# -*- coding: utf-8 -*-



import sys

from collections import Counter



def input(): return sys.stdin.readline().strip()

def list2d(a, b, c): return [[c] * b for i in range(a)]

def list3d(a, b, c, d): return [[[d] * c for j in range(b)] for i in range(a)]

def list4d(a, b, c, d, e): return [[[[e] * d for j in range(c)] for j in range(b)] for i in range(a)]

def ceil(x, y=1): return int(-(-x // y))

def INT(): return int(eval(input()))

def MAP(): return list(map(int, input().split()))

def LIST(N=None): return list(MAP()) if N is None else [INT() for i in range(N)]

def Yes(): print('Yes')

def No(): print('No')

def YES(): print('YES')

def NO(): print('NO')

sys.setrecursionlimit(10 ** 9)

INF = float('inf')

MOD = 10 ** 9 + 7



N = INT()

S = eval(input())



S1 = list(S[:N])

# 左右同じものを目指す形にしたいので、片方はリバースしておく

S2 = list(S[N:])[::-1]



d1 = Counter()

d2 = Counter()

# 半分に分けた両方を組み合わせ全列挙

for i in range(1<<N):

    s1_1, s1_2 = [], []

    s2_1, s2_2 = [], []

    for j in range(N):

        if i>>j & 1:

            s1_1 += [S1[j]]

            s2_1 += [S2[j]]

        else:

            s1_2 += [S1[j]]

            s2_2 += [S2[j]]

    # 文字列ペアをキーとして、その通り数を数えておく

    d1[(''.join(s1_1), ''.join(s1_2))] += 1

    d2[(''.join(s2_1), ''.join(s2_2))] += 1



ans = 0

for k, v in list(d1.items()):

    # 左文字列ペア = 右文字列ペア になるような通り数を数え上げる

    ans += v * d2[k]

print(ans)

# -*- coding: utf-8 -*-



import sys

from collections import Counter



def input(): return sys.stdin.readline().strip()

def list2d(a, b, c): return [[c] * b for i in range(a)]

def list3d(a, b, c, d): return [[[d] * c for j in range(b)] for i in range(a)]

def list4d(a, b, c, d, e): return [[[[e] * d for j in range(c)] for j in range(b)] for i in range(a)]

def ceil(x, y=1): return int(-(-x // y))

def INT(): return int(eval(input()))

def MAP(): return list(map(int, input().split()))

def LIST(N=None): return list(MAP()) if N is None else [INT() for i in range(N)]

def Yes(): print('Yes')

def No(): print('No')

def YES(): print('YES')

def NO(): print('NO')

sys.setrecursionlimit(10 ** 9)

INF = float('inf')

MOD = 10 ** 9 + 7



N = INT()

S = eval(input())



S1 = S[:N]

# 左右同じものを目指す形にしたいので、片方はリバースしておく

S2 = S[N:][::-1]



d1 = Counter()

d2 = Counter()

# 半分に分けた両方を組み合わせ全列挙

for i in range(1<<N):

    s1_1, s1_2 = '', ''

    s2_1, s2_2 = '', ''

    for j in range(N):

        if i>>j & 1:

            s1_1 += S1[j]

            s2_1 += S2[j]

        else:

            s1_2 += S1[j]

            s2_2 += S2[j]

    # 文字列ペアをキーとして、その通り数を数えておく

    d1[(s1_1, s1_2)] += 1

    d2[(s2_1, s2_2)] += 1



ans = 0

for k, v in list(d1.items()):

    # 左文字列ペア = 右文字列ペア になるような通り数を数え上げる

    ans += v * d2[k]

print(ans)

# -*- coding: utf-8 -*-
import sys
from collections import Counter


def input():
    return sys.stdin.readline().strip()


def list2d(a, b, c):
    return [[c] * b for i in range(a)]


def list3d(a, b, c, d):
    return [[[d] * c for j in range(b)] for i in range(a)]


def list4d(a, b, c, d, e):
    return [[[[e] * d for j in range(c)] for j in range(b)] for i in range(a)]


def ceil(x, y=1):
    return int(-(-x // y))


def INT():
    return int(eval(input()))


def MAP():
    return list(map(int, input().split()))


def LIST(N=None):
    return list(MAP()) if N is None else [INT() for i in range(N)]


def Yes():
    print("Yes")


def No():
    print("No")


def YES():
    print("YES")


def NO():
    print("NO")


sys.setrecursionlimit(10**9)
INF = float("inf")
MOD = 10**9 + 7
N = INT()
S = eval(input())
S1 = list(S[:N])
# 左右同じものを目指す形にしたいので、片方はリバースしておく
S2 = list(S[N:])[::-1]
d1 = Counter()
d2 = Counter()
# 半分に分けた両方を組み合わせ全列挙
for i in range(1 << N):
    s1_1, s1_2 = [], []
    s2_1, s2_2 = [], []
    for j in range(N):
        if i >> j & 1:
            s1_1 += [S1[j]]
            s2_1 += [S2[j]]
        else:
            s1_2 += [S1[j]]
            s2_2 += [S2[j]]
    # 文字列ペアをキーとして、その通り数を数えておく
    d1[("".join(s1_1), "".join(s1_2))] += 1
    d2[("".join(s2_1), "".join(s2_2))] += 1
ans = 0
for k, v in list(d1.items()):
    # 左文字列ペア = 右文字列ペア になるような通り数を数え上げる
    ans += v * d2[k]
print(ans)

# -*- coding: utf-8 -*-
import sys
from collections import Counter


def input():
    return sys.stdin.readline().strip()


def list2d(a, b, c):
    return [[c] * b for i in range(a)]


def list3d(a, b, c, d):
    return [[[d] * c for j in range(b)] for i in range(a)]


def list4d(a, b, c, d, e):
    return [[[[e] * d for j in range(c)] for j in range(b)] for i in range(a)]


def ceil(x, y=1):
    return int(-(-x // y))


def INT():
    return int(eval(input()))


def MAP():
    return list(map(int, input().split()))


def LIST(N=None):
    return list(MAP()) if N is None else [INT() for i in range(N)]


def Yes():
    print("Yes")


def No():
    print("No")


def YES():
    print("YES")


def NO():
    print("NO")


sys.setrecursionlimit(10**9)
INF = float("inf")
MOD = 10**9 + 7
N = INT()
S = eval(input())
S1 = S[:N]
# 左右同じものを目指す形にしたいので、片方はリバースしておく
S2 = S[N:][::-1]
d1 = Counter()
d2 = Counter()
# 半分に分けた両方を組み合わせ全列挙
for i in range(1 << N):
    s1_1, s1_2 = "", ""
    s2_1, s2_2 = "", ""
    for j in range(N):
        if i >> j & 1:
            s1_1 += S1[j]
            s2_1 += S2[j]
        else:
            s1_2 += S1[j]
            s2_2 += S2[j]
    # 文字列ペアをキーとして、その通り数を数えておく
    d1[(s1_1, s1_2)] += 1
    d2[(s2_1, s2_2)] += 1
ans = 0
for k, v in list(d1.items()):
    # 左文字列ペア = 右文字列ペア になるような通り数を数え上げる
    ans += v * d2[k]
print(ans)

-S1 = list(S[:N]) +S1 = S[:N] -S2 = list(S[N:])[::-1] +S2 = S[N:][::-1] -    s1_1, s1_2 = [], [] -    s2_1, s2_2 = [], [] +    s1_1, s1_2 = "", "" +    s2_1, s2_2 = "", "" -            s1_1 += [S1[j]] -            s2_1 += [S2[j]] +            s1_1 += S1[j] +            s2_1 += S2[j] -            s1_2 += [S1[j]] -            s2_2 += [S2[j]] +            s1_2 += S1[j] +            s2_2 += S2[j] -    d1[("".join(s1_1), "".join(s1_2))] += 1 -    d2[("".join(s2_1), "".join(s2_2))] += 1 +    d1[(s1_1, s1_2)] += 1 +    d2[(s2_1, s2_2)] += 1