爬山 import java.awt.List; import java.util.ArrayList; import java.util.Collections; import java.util.Scanner; public class Main1 {               public static ArrayList<Integer> list=new ArrayList<>();          public static void main(String[] args) {         System.out.println("Hello World");                  Scanner scanner=new Scanner(System.in);                  int n=scanner.nextInt();         int m=scanner.nextInt();                  int x=scanner.nextInt();         int y=scanner.nextInt();                           int a[][]=new int[n][m];                  for (int i = 0; i <n; i++) {             for(int j=0;j<m;j++) {                 a[i][j]=scanner.nextInt();             }                      }                  scanner.close();                  list.add(a[x-1][y-1]);         countWays(a,n,m,x-1,y-1);                            Collections.sort(list);                  System.out.println(list.get(list.size()-1));     }     private static void countWays(int[][] a, int n, int m, int x, int y) {                  int l1,l2,l3,l4;         l1=x+1;         l2=x-1;         l3=y+1;         l4=y-1;                                    if(l3>0&&l3<m) {             if(a[x][l3]>a[x][y]) {                              list.add(a[x][l3]);                 countWays(a, n, m, x, l3);             }         }                  if(l4>0&&l4<m) {             if(a[x][l4]>a[x][y]) {                 list.add(a[x][l4]);                 countWays(a, n, m, x, l4);             }                      }                  if(l1>0&&l1<n) {             if(a[l1][y]>a[x][y]) {                      list.add(a[l1][y]);                 countWays(a, n, m, l1, y);             }                      }                  if(l2>0&&l2<n) {                          if(a[l2][y]>a[x][y]) {                 list.add(a[l2][y]);                 countWays(a, n, m, l2, y);             }         }                                }                          }