from collections import deque
N,M,K=map(int,input().split())
A=[]
for _ in range(N):
    A.append(list(map(int,input().split())))

def nibun(f):
    left,right=0,10**9+1
    while right-left>1:
        mid=(right+left)//2
        if f(mid):
            left=mid
        else:
            right=mid
    return left

def isok(n):
    if bfs((0,0),n)<=K:
        return True
    return False

def bfs(s,n):
    dq=deque()
    high=[[10**9 for _ in range(M)] for _ in range(N)]
    if A[0][0]<n:
        high[s[0]][s[1]]=1
        dq.append([s[0],s[1],1])
    else:
        high[s[0]][s[1]]=0
        dq.append([s[0],s[1],0])
    while len(dq)!=0:
        i,j,h=dq.popleft()
        for d1,d2 in [[1,0],[-1,0],[0,1],[0,-1]]:
            x=i+d1
            y=j+d2
            if 0<=x<N and 0<=y<M and high[x][y]==10**9:
                if A[x][y]<n:
                    dq.append([x,y,h+1])
                    high[x][y]=h+1
                else:
                    dq.append([x,y,h])
                    high[x][y]=h
    return high[-1][-1]

print(nibun(isok))