n=len(grid)
    c=0
    for i in range(1,n-1):
        for j in range(1,n-1):
            if grid[i][j]>grid[i][j-1] and grid[i][j]>grid[i][j+1] and grid[i][j]>grid[i-1][j] and grid[i][j]>grid[i+1][j]:
                p=list(grid[i])
                p[j]='X'
                grid[i]=''.join(p)
    return grid

 int left = 1;
    int right = grid[0].size() - 2;
    int top = 1;
    int bottom = grid.size() - 2;

    for (int i = top; i <= bottom; i++)
    {
        for (int j = left; j <= right; j++)
        {
            if (grid[i - 1][j] < grid[i][j] and grid[i + 1][j] < grid[i][j] and grid[i][j - 1] < grid[i][j] and grid[i][j + 1] < grid[i][j]){
                // cout<<"here";
                grid[i][j] = 'X';
            }
            
        }
    }
    return grid;

public static List<String> cavityMap(List<String> grid) {
        
        List<String> result = new ArrayList<>();
        result.add(grid.get(0));
        
        for(int i = 1; i < grid.size() - 1; i++) {
            
            String temp = "";
            
            char topRow[] = grid.get(i - 1).toCharArray();
            char curRow[] = grid.get(i).toCharArray();
            char bottomRow[] = grid.get(i + 1).toCharArray();
            
            // border
            temp += String.valueOf(curRow[0]);
            
            for(int j = 1; j < curRow.length - 1; j++) {
                
                char top = topRow[j];
                char left = curRow[j - 1];
                char current = curRow[j];
                char right = curRow[j + 1];
                char bottom = bottomRow[j];
                
                if(current > left 
                    && current > right
                    && current > top
                    && current > bottom) {
                    
                    temp += "X";
                } else {
                    
                    temp += String.valueOf(current);
                }
                
            }
            
            // border
            temp += String.valueOf(curRow[curRow.length - 1]);
            result.add(temp);
        }
        
        if(grid.size() > 1) {
            result.add(grid.get(grid.size() - 1));
        }
    
        return result;
    }