import sys
input = sys.stdin.readline

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

    
from collections import *
def check(mid):
    inf = 10 ** 18
    D = [[inf] * N for _ in range(N)]
    Q = deque()
    D[0][0] = int(A[0][0] < mid)
    dx = [1, 0, -1, 0]
    dy = [0, 1, 0, -1]
    Q.append((0, 0))
    while Q:
        px, py = Q.popleft()
        for k in range(4):
            x, y = px + dx[k], py + dy[k]
            if x < 0 or x > N - 1 or y < 0 or y > N - 1:
                continue
            if D[x][y] != inf and D[x][y] <= D[px][py] + int(A[x][y] < mid):
                continue
            D[x][y] = D[px][py] + int(A[x][y] < mid)
            if A[x][y] < mid:
                Q.append((x, y))
            else:
                Q.appendleft((x, y))
    return D[N-1][N-1] 
    
    
def BinarySearch(yes = 10 ** 18, no = -1):
    while abs(yes - no) != 1:
        mid = (yes + no)//2
        if check(mid) <= K:
            yes = mid
        else:
            no = mid
    return yes

print(BinarySearch(1, 10**9+1))