def popcount(x):
    x = x - ((x >> 1) & 0x55555555)
    x = (x & 0x33333333) + ((x >> 2) & 0x33333333)
    x = (x + (x >> 4)) & 0x0f0f0f0f
    x += x >> 8
    x += x >> 16
    return x & 0x0000003f

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

ans = 1 << 30
for bit in range(1 << n):
    pc = popcount(bit)
    if pc > m or pc + n < m:
        continue
    tmp = 0
    lst = [0] * n
    for i in range(n):
        if bit >> i & 1:
            for j in range(n):
                tmp += A[i][j]
        else:
            for j in range(n):
                lst[j] += A[i][j]
    lst.sort()
    tmp += sum(lst[:m - pc])
    ans = min(ans, tmp)
    
x = 0
for i in range(n):
    x += A[i][i]
    
for bit in range(1 << n):
    pc = popcount(bit) + 1
    if pc > m or pc + n < m:
        continue
    tmp = x
    lst = [0] * n
    for i in range(n):
        if bit >> i & 1:
            for j in range(n):
                if i != j:
                    tmp += A[i][j]
        else:
            for j in range(n):
                if i != j:
                    lst[j] += A[i][j]
    lst.sort()
    tmp += sum(lst[:m - pc])
    ans = min(ans, tmp)
    
    
x = 0
for i in range(n):
    x += A[i][n - 1 - i]
    
for bit in range(1 << n):
    pc = popcount(bit) + 1
    if pc > m or pc + n < m:
        continue
    tmp = x
    lst = [0] * n
    for i in range(n):
        if bit >> i & 1:
            for j in range(n):
                if i != n - 1 - j:
                    tmp += A[i][j]
        else:
            for j in range(n):
                if i != n - 1 - j:
                    lst[j] += A[i][j]
    lst.sort()
    tmp += sum(lst[:m - pc])
    ans = min(ans, tmp)


x = 0
for i in range(n):
    x += A[i][i]
    if i != n - 1 - i:
        x += A[i][n - 1 - i]
    
for bit in range(1 << n):
    pc = popcount(bit) + 2
    if pc > m or pc + n < m:
        continue
    tmp = x
    lst = [0] * n
    for i in range(n):
        if bit >> i & 1:
            for j in range(n):
                if i != n - 1 - j and i != j:
                    tmp += A[i][j]
        else:
            for j in range(n):
                if i != n - 1 - j and i != j:
                    lst[j] += A[i][j]
    lst.sort()
    tmp += sum(lst[:m - pc])
    ans = min(ans, tmp)

print(ans)