func countBattleships(_ board: [[Character]]) -> Int {
        var res:Int = 0
        for i in 0..<board.count {
            for j in 0..<board[i].count {
                if i>0 && board[i-1][j] == "X"{
                    continue
                } else if j>0 && board[i][j-1] == "X" {
                    continue
                } else if i>0 && j>0 {
                    if board[i-1][j] == "." && board[i][j-1] == "." && board[i][j] == "X"{
                        res += 1
                    }
                    continue
                } else if board[i][j] == "X" {
                    res += 1
                }
            }
        }
        return res
    }