n,m = map(int,input().split())
a = [list(map(int,input().split())) for _ in range(n)]

N = (1<<(n+2))
cnt = [0]*N
for i in range(n+2):
    for j in range(1<<i):
        cnt[j+(1<<i)] = cnt[j]+1
ans = 10**9
for mask in range(N):
    cm = cnt[mask]
    if cm > m: continue
    res = [0]*n
    val = 0
    for i in range(n):
        for j in range(n):
            if mask>>j&1 or (j == i and mask>>n&1) or (j == n-1-i and mask>>(n+1)&1):
                val += a[i][j]
            else:
                res[i] += a[i][j]
    res.sort()
    val += sum(res[:m-cm])
    ans = min(ans,val)
print(ans)