N = int(input())
C = [input() for i in range(N)]

MOD = 998244353

from collections import Counter
cs = [Counter() for _ in range(N)]
for b in range(1<<(N-1)):
    i = j = 0
    s = [C[0][0]]
    for k in range(N-1):
        if b&(1<<k):
            i += 1
        else:
            j += 1
        s.append(C[i][j])
    cs[i][''.join(s)] += 1

ans = 0
for b in range(1<<(N-1)):
    i = j = N-1
    s = [C[-1][-1]]
    for k in range(N-1):
        if b&(1<<k):
            i -= 1
        else:
            j -= 1
        s.append(C[i][j])
    ans += cs[i][''.join(s)]
    ans %= MOD

print(ans)