import sys
input = sys.stdin.readline

N,M=map(int,input().split())
A=[]
for i in range(N):
    A.extend(list(map(int,input().split())))

ANS=1<<30
for i in range(1<<(N+2)):
    
    x=0
    for j in range(N+2):
        if (1<<j) & i !=0:
            x+=1

    r=M-x

    if r<0 or r>N:
        continue

    B=[0]*(N*N)

    for j in range(N+2):
        if (1<<j) & i != 0:
            if j<N:
                for k in range(N):
                    B[k*N+j]=1
            elif j==N:
                for k in range(N):
                    B[k*N+k]=1
            else:
                for k in range(N):
                    B[k*N+N-k-1]=1

    SCORE=0
    C=[]

    for j in range(N):
        sc=0
        for k in range(N):
            if B[j*N+k]==1:
                SCORE+=A[j*N+k]
            else:
                sc+=A[j*N+k]
        C.append(sc)

    C.sort()

    ANS=min(ANS,SCORE+sum(C[:r]))

print(ANS)