from collections import deque
n, m, k = map(int, input().split())
a = [list(map(int, input().split())) for _ in range(n)]
inf = 1 << 30
l, r = 0, inf
while r - l > 1:
  piv = (l + r) // 2
  dist = [inf] * (n * m)
  dist[0] = a[0][0] < piv
  d = deque([dist[0]*n*m])
  while d:
    c, u = divmod(d.popleft(), n*m)
    if u == n * m - 1:
    	break
    i, j = u // m, u % m
    if 0 < i:
      dis = c + (a[i-1][j] < piv)
      if dis < dist[u-m] and dis <= k:
        dist[u-m] = dis
        if a[i-1][j] < piv:
          d.append(dis*n*m+u-m)
        else:
          d.appendleft(dis*n*m+u-m)
    if i < n - 1:
      dis = c + (a[i+1][j] < piv)
      if dis < dist[u+m] and dis <= k:
        dist[u+m] = dis
        if a[i+1][j] < piv:
          d.append(dis*n*m+u+m)
        else:
          d.appendleft(dis*n*m+u+m)
    if 0 < j:
      dis = c + (a[i][j-1] < piv)
      if dis < dist[u-1] and dis <= k:
        dist[u-1] = dis
        if a[i][j-1] < piv:
          d.append(dis*n*m+u-1)
        else:
          d.appendleft(dis*n*m+u-1)
    if j < m - 1:
      dis = c + (a[i][j+1] < piv)
      if dis < dist[u+1] and dis <= k:
        dist[u+1] = dis
        if a[i][j+1] < piv:
          d.append(dis*n*m+u+1)
        else:
          d.appendleft(dis*n*m+u+1)
  if dist[n*m-1] <= k:
    l = piv
  else:
    r = piv
print(min(l, 10**9))