N,M = map(int,input().split())
A = [list(map(int,input().split())) for _ in range(N)]
ans = 10**5
for i in range(1<<N):
    tot = 0
    n = 0
    for k in range(N):
        if i>>k & 1:
            n += 1
            for j in range(N):
                tot += A[k][j]
    if n>M:continue
    B = []
    for j in range(N):
        cnt = 0
        for k in range(N):
            if i>>k & 1:continue
            cnt += A[k][j]
        B.append(cnt)
    B = sorted(B)
    for j in range(M-n):
        tot += B[j]
    ans = min(ans,tot)
tot = 0
for i in range(N):
    tot += A[i][i]
if M==1:
    ans = min(ans,tot)
else:
    for i in range(1<<N):
        tot1 = tot
        n = 1
        for k in range(N):
            if i>>k & 1:
                n += 1
                for j in range(N):
                    if j==k:continue
                    tot1 += A[k][j]
        if n>M:continue
        B = []
        for j in range(N):
            cnt = 0
            for k in range(N):
                if i>>k & 1:continue
                if k==j:continue
                cnt += A[k][j]
            B.append(cnt)
        B = sorted(B)
        for j in range(M-n):
            tot1 += B[j]
        ans = min(ans,tot1)
tot = 0
for i in range(N):
    tot += A[i][N-1-i]
if M==1:
    ans = min(ans,tot)
else:
    for i in range(1<<N):
        tot1 = tot
        n = 1
        for k in range(N):
            if i>>k & 1:
                n += 1
                for j in range(N):
                    if j==N-1-k:continue
                    tot1 += A[k][j]
        if n>M:continue
        B = []
        for j in range(N):
            cnt = 0
            for k in range(N):
                if i>>k & 1:continue
                if k==N-1-j:continue
                cnt += A[k][j]
            B.append(cnt)
        B = sorted(B)
        for j in range(M-n):
            tot1 += B[j]
        ans = min(ans,tot1)
if M>=2:
    tot = 0
    for i in range(N):
        tot += A[i][i]+A[i][N-1-i]
    if N%2==1:
        tot -= A[N//2][N//2]
    if M==2:
        ans = min(ans,tot)
    else:
        for i in range(1<<N):
            tot1 = tot
            n = 2
            for k in range(N):
                if i>>k & 1:
                    n += 1
                    for j in range(N):
                        if j==k or j==N-1-k:continue
                        tot1 += A[k][j]
            if n>M:continue
            B = []
            for j in range(N):
                cnt = 0
                for k in range(N):
                    if i>>k & 1:continue
                    if k==j or k==N-1-j:continue
                    cnt += A[k][j]
                B.append(cnt)
            B = sorted(B)
            for j in range(M-n):
                tot1 += B[j]
            ans = min(ans,tot1)
print(ans)