def gridChallenge(grid):
    # rearrange elements for rows
    rows = [sorted(list(row_str)) for row_str in grid]

    # check for columns order
    for col in zip(*rows):
        for j in range(len(col)-1):
            if col[j] > col[j+1]:
                return 'NO'
    return 'YES'

def gridChallenge(grid):
    rows = len(grid)
    long = len(grid[0])
    mx = [list(row) for row in grid]
    
    # rearrange elements for rows
    for idx, row in enumerate(mx):
        mx[idx] = sorted(row)
        
    # check for columns order
    for i in range(long):
        checking = []
        for row in mx:
            checking.append(row[i])
        print(i,checking,sep=":")
        for j in range(rows-1):
            if checking[j] > checking[j+1]:
                return 'NO'
    return 'YES'

public static String gridChallenge(List<String> grid) {
        for (int i = 0; i < grid.size(); i++) {
            char[] ca = grid.get(i).toCharArray();
            Arrays.sort(ca);
            grid.set(i, String.valueOf(ca));
        }
        
        for (int j = 0; j < grid.get(0).length(); j++) {
            for (int i = 1; i < grid.size(); i++) {
                if (grid.get(i).charAt(j) < grid.get(i - 1).charAt(j)) return "NO";
            }
        }
        
        return "YES";
    }