import sys
# Constants
MAXN = 505
INF = int(1e9)
# Global variables
edge = [[0] * MAXN for _ in range(MAXN)]
dp = [[[0, 0] for _ in range(MAXN)] for _ in range(MAXN)]
dp1 = [[[0, 0] for _ in range(MAXN)] for _ in range(MAXN)]
nx = [[0, 0] for _ in range(MAXN)]
n = 0
type_ = 0
def solve(l, r, x):
if edge[l][r]:
dp[l][r][x] = 1
dp1[l][r][x] = 1 + dp1[r][nx[l][x]][x ^ 1]
else:
dp[l][r][x] = -n
dp1[l][r][x] = -n
m = nx[l][x]
while m != r:
dp[l][r][x] = max(dp[l][r][x], dp[l][m][x] + dp[m][r][x])
dp1[l][r][x] = max(dp1[l][r][x], dp[l][m][x] + dp1[m][r][x])
m = nx[m][x]
dp1[l][r][x] = max(dp1[l][r][x], dp1[l][nx[r][x ^ 1]][x])
def main():
global n, type_
n, type_ = map(int, input().split())
for i in range(n):
data = list(map(int, input().split()))
idx = 0
while data[idx] != 0:
edge[i][data[idx] - 1] = 1
idx += 1
nx[i][0] = (i + 1) % n
nx[i][1] = (i + n - 1) % n
for d in range(1, n):
for l in range(n):
r = (l + d) % n
solve(l, r, 0)
solve(r, l, 1)
ans = (-1, 0)
for l in range(n):
for r in range(n):
for x in range(2):
ans = max(ans, (dp1[l][r][x], l + 1))
if type_:
for l in range(n):
for r in range(n):
for x in range(2):
if dp[l][r][x] <= 0:
continue
st = nx[r][x]
while st != l and edge[st][l] == 0:
st = nx[st][x]
if st == l:
continue
ed = nx[st][x]
while ed != l:
if edge[r][ed]:
ans = max(ans, (max(dp1[ed][nx[l][x ^ 1]][x], dp1[ed][nx[st][x]][x ^ 1]) + 2 + dp[l][r][x], st + 1))
ed = nx[ed][x]
print(ans[0])
# print(ans[1])
if __name__ == '__main__':
main()
