import java.io.*;
import java.util.*;
import java.util.function.*;
import java.util.stream.*;

public class Main {
    public static void main(String[] args) throws Exception {
        Scanner sc = new Scanner();
        int h = sc.nextInt();
        int w = sc.nextInt();
        int k = sc.nextInt();
        int[][] field = new int[h][w];
        for (int i = 0; i < h; i++) {
            for (int j = 0; j < w; j++) {
                field[i][j] = sc.nextInt();
            }
        }
        int left = 0;
        int right = 1000000001;
        Deque<Path> deq = new ArrayDeque<>();
        while (right - left > 1) {
            int m = (left + right) / 2;
            deq.add(new Path(0, 0, 0));
            int[][] counts = new int[h][w];
            for (int[] arr : counts) {
                Arrays.fill(arr, Integer.MAX_VALUE);
            }
            while (deq.size() > 0) {
                Path p = deq.poll();
                if (field[p.r][p.c] < m) {
                    p.value++;
                }
                if (counts[p.r][p.c] <= p.value) {
                    continue;
                }
                counts[p.r][p.c] = p.value;
                if (p.r > 0 && counts[p.r - 1][p.c] == Integer.MAX_VALUE) {
                    deq.add(new Path(p.r - 1, p.c, p.value));
                }
                if (p.r < h - 1 && counts[p.r + 1][p.c] == Integer.MAX_VALUE) {
                    deq.add(new Path(p.r + 1, p.c, p.value));
                }
                if (p.c > 0 && counts[p.r][p.c - 1] == Integer.MAX_VALUE) {
                    deq.add(new Path(p.r, p.c - 1, p.value));
                }
                if (p.c < w - 1 && counts[p.r][p.c + 1] == Integer.MAX_VALUE) {
                    deq.add(new Path(p.r, p.c + 1, p.value));
                }
            }
            if (counts[h - 1][w - 1] <= k) {
                left = m;
            } else {
                right = m;
            }
        }
        System.out.println(left);
    }
    
    static class Path {
        int r;
        int c;
        int value;
        
        public Path(int r, int c, int value) {
            this.r = r;
            this.c = c;
            this.value = value;
        }
    }
}

class Scanner {
    BufferedReader br;
    StringTokenizer st = new StringTokenizer("");

    public Scanner() {
        try {
            br = new BufferedReader(new InputStreamReader(System.in));
        } catch (Exception e) {
            
        }
    }
    
    public int nextInt() {
        return Integer.parseInt(next());
    }
    
    public long nextLong() {
        return Long.parseLong(next());
    }
    
    public double nextDouble() {
        return Double.parseDouble(next());
    }
    
    public String next() {
        try {
            while (!st.hasMoreTokens()) {
                st = new StringTokenizer(br.readLine());
            }
        } catch (Exception e) {
            e.printStackTrace();
        } finally {
            return st.nextToken();
        }
    }
    
}