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

ans = 10**18
for x in range(2):
    for y in range(2):
        for i in range(1 << n):
            su = 0
            b = [j[:] for j in a]
            ok = x+y
            if x:
                for j in range(n):
                    su += b[j][j]
                    b[j][j] = 0
            if y:
                for j in range(n):
                    su += b[j][n-1-j]
                    b[j][n-1-j] = 0
            for j in range(n):
                if (i >> j) & 1 == 1:
                    ok += 1
                    for k in range(n):
                        su += b[k][j]
                        b[k][j] = 0
            c = [sum(j) for j in b]
            c.sort()
            su += sum(c[:max(0, m-ok)])
            ans = min(ans, su)
print(ans)