private void fillBoard(){
        for(int i = 0;i < board.length;i++){
            for(int j = 0;j < board.length;j++){
                if(i == 0 || j == 0 || i == 49 || j == 49){
                    board[i][j] = 1;
                }
                else{
                    board[i][j] = 0;
                }
            }
        }
    }