public int islandPerimeter(int[][] grid) {
        int result = 0;
        for(int i=0;i<grid.length;i++){
            for(int j=0;j<grid[0].length;j++){
//this '{' include neighbor case
                if(grid[i][j]==1){
                    result += 4;

         if(i>0&&grid[i-1][j]==1) result -= 2;
         if(j>0&&grid[i][j-1]==1) result -= 2;
            }
        }}return result;
    }