exec("def nWord(): nWord.cache = raw_input() if not hasattr(nWord, 'cache') or nWord.cache=='' else nWord.cache ; pos = nWord.cache.find(nWord.sep) ; ret, nWord.cache = (nWord.cache, '') if pos==-1 else (nWord.cache[:pos], nWord.cache[pos+1:].lstrip(nWord.sep)) ; return ret") ; exec("nWord.sep = ' '") ; exec("def ___nLine2(): ret, nWord.cache = (raw_input(), nWord.cache if hasattr(nWord, 'cache') else '') if not hasattr(nWord, 'cache') or nWord.cache=='' else (nWord.cache, '') ; return ret") ; exec('def nInt(): return int(nWord())') ; exec('def nFloat(): return float(nWord())') ; exec("def ___nAuto2():\n ret = nWord()\n try: return int(ret)\n except: pass\n try: return float(ret)\n except: return ret") ; exec("def nAuto(n=None): return ___nAuto2() if n is None else [___nAuto2() for i in range(n)]") ; exec("def nLine(n=None): return ___nLine2() if n is None else [___nLine2() for i in range(n)]")
 
N = nAuto()
S = nAuto(N)

def check(A):
    for i in range(N):
        for j in range(N):
            if S[(A+i) % N][j]!=S[(A+j) % N][i]:
                return 0
    return N
 
count = 0
for A in range(N):
    count += check(A)
print count
