"""

bitdpではだめ
斜めは4通り試せばよいか

フローで解けないか…？

貪欲…？
最後の1方向は貪欲でおk
あ、

2**18 * 貪欲

"""

from sys import stdin

N,M = map(int,stdin.readline().split())

A = []
ans = float("inf")

for i in range(N):
    A.append(list(map(int,stdin.readline().split())))

for i in range(2**(N+2)):

    B = [[A[i][j] for j in range(N)] for i in range(N)]

    rem = M
    tmp = 0
    for y in range(N):
        if 2**y & i > 0:
            rem -= 1
            for x in range(N):
                tmp += B[x][y]
                B[x][y] = 0

    y = N
    if 2**y & i > 0:
        rem -= 1
        for k in range(N):
            tmp += B[k][k]
            B[k][k] = 0

    y = N+1
    if 2**y & i > 0:
        rem -= 1
        for k in range(N):
            tmp += B[k][N-k-1]
            B[k][N-k-1] = 0

    if rem < 0:
        ans = min(ans,tmp)
    else:
        lis = [sum(B[j]) for j in range(N)]
        lis.sort()
        tmp += sum(lis[:rem])
        ans = min(ans,tmp)
        
print (ans)