Untitled

import java.util.*;

public class Main {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        int r = sc.nextInt(), c = sc.nextInt();
        int[][] island = new int[r][c];
        for (int i = 0; i < r; i++) {
            for (int j = 0; j < c; j++) {
                island[i][j] = sc.nextInt();
            }
        }
        sc.close();
        System.out.println(islandPerimeter(island));
    }

    public static int islandPerimeter(int[][] grid) {
        // your code here
		if (grid == null) return 0;
        for (int i = 0 ; i < grid.length ; i++){
            for (int j = 0 ; j < grid[0].length ; j++){
                if (grid[i][j] == 1) {
                    return getPerimeter(grid,i,j);
                }
            }
        }
        return 0;
    }
    
    public static int getPerimeter(int[][] grid, int i, int j){
        if (i < 0 || i >= grid.length || j < 0 || j >= grid[0].length) {return 1;}
        if (grid[i][j] == 0) {
            return 1;
        }
        if (grid[i][j] == -1) return 0;
        
        int count = 0;
        grid[i][j] = -1;
        
        count += getPerimeter(grid, i-1, j);
        count += getPerimeter(grid, i, j-1);
        count += getPerimeter(grid, i, j+1);
        count += getPerimeter(grid, i+1, j);
        
        return count;
        
    }
}