DY = [1, 0, -1, 0]
DX = [0, 1, 0, -1]
n, m, k = read_line.split.map(&.to_i)
a = Array.new(n) { read_line.split.map(&.to_i) }
lo = 1
hi = 1_000_000_001
while hi - lo > 1
  mid = (lo + hi) // 2
  if count(a, mid) <= k
    lo = mid
  else
    hi = mid
  end
end
puts lo

def count(a, v)
  h = a.size
  w = a[0].size
  q = Deque(Tuple(Int32, Int32)).new
  c = Array.new(h) { Array.new(w, -1) }
  c[0][0] = a[0][0] < v ? 1 : 0
  q << {0, 0}
  while !q.empty?
    y, x = q.shift
    4.times do |d|
      ny = y + DY[d]
      nx = x + DX[d]
      if 0 <= ny < h && 0 <= nx < w && c[ny][nx] == -1
        if a[ny][nx] < v
          c[ny][nx] = c[y][x] + 1
          q << {ny, nx}
        else
          c[ny][nx] = c[y][x]
          q.unshift({ny, nx})
        end
      end
    end
  end
  c[-1][-1]
end