def read_data():
    N, M = map(int, input().split())
    Cs = []
    for m in range(M):
        mat = [list(map(int, input().split())) for n in range(N)]
        Cs.append(mat)
    return N, M, Cs

def solve(N, M, Cs):
    mymax = max
    mysum = sum
    maxC = mymax(mymax(mymax(c) for c in C) for C in Cs)
    Ds = C2D(N, M, Cs)
    record = 0
    bits = [0] * (maxC + 1)
    for i, D in enumerate(Ds):
        for d in D:
            for di in d:
                bits[di] = 1
            for E in Ds[i + 1:]:
                for e in E:
#                    counts = len([1 for ei in e if bits[ei]])
                    counts = mysum([bits[ei] for ei in e])
                    if counts > record:
                        record = counts
            for di in d:
                bits[di] = 0
        if record == N:
            return N - 1
    return 2 * N - 1 - record

def C2D(N, M, Cs):
    return [c2d(N, C) for C in Cs]

def c2d(N, C):
    d = []
    for c in C: d.append(c[:])
    Ct = list(zip(*C))
    for ct in Ct: d.append(list(ct))
    diagonal1 = [C[i][i] for i in range(N)]
    d.append(diagonal1)
    diagonal2 = [C[N - 1 - i][i] for i in range(N)]
    d.append(diagonal2)
    return d

N, M, Cs = read_data()
print(solve(N, M, Cs))