using System;

using System.Collections.Generic;

using System.Text;

public abstract class Statement

{

}

public class DeclareVariable : Statement

{

    public string Identifier;

    public Expression Expression;

}

public class DeclareFunction : Statement 

{

    public string FunctionName;

    public DeclareVariable Parameter1;

    public DeclareVariable Parameter2;

    public DeclareVariable Parameter3;

    public String ReturnType;

    public Statement Body;

}

public class CallFunction : Statement 

{

    public string FunctionName;

    public Expression Parameter1;

    public Expression Parameter2;

    public Expression Parameter3;

    public Identifier ReturnVariable;

}

public class Write : Statement

{

    public Expression Expression;

}

public class Assignment : Statement

{

    public string Identifier;

    public Expression Expression;

}

public class For : Statement

{

    public string Identifier;

    public Expression From;

    public Expression To;

    public Statement Body;

}

public class IfThenElse : Statement

{

    public Expression If;

    public Statement Then;

    public Statement Else;

}

public class IfThen : Statement

{

    public Expression LeftExpression;

    public RelationalOperands Operand;

    public Expression RightExpression;

    public Statement ThenBody;

    public Statement ElseBody;

}

public class While : Statement

{

    public Expression LeftExpression;

    public RelationalOperands Operand;

    public Expression RightExpression;

    public Statement Body;

}

public class ReadInput : Statement

{

    public string Identifier;

}

public class StatementSequence : Statement

{

    public Statement Left;

    public Statement Right;

}

public abstract class Expression

{

}

public class AlphaNumericValue : Expression

{

    public string Value;

}

public class NumericValue : Expression

{

    public int Value;

}

public class Identifier : Expression

{

    public string IdentifierName;

}

public class ArithmaticExpression : Expression

{

    public Expression Left;

    public Expression Right;

    public ArithmaticOperands Operand;

}

public enum ArithmaticOperands

{

    Add,

    Subtract,

    Multiply,

    Division

}

public class LogicalExpression : Expression

{

    public Expression Left;

    public Expression Right;

    public LogicalOperands Operand;

}

public enum LogicalOperands

{

    Or,

    And,

    Xor,

    Not

}

public class RelationalExpression : Expression

{

    public Expression Left;

    public Expression Right;

    public RelationalOperands Operand;

}

public class CompareVariable : Statement

{

    public string Identifier;

    public Expression Expression;

    public RelationalOperands Operand;

}

public enum RelationalOperands

{

    EqualTo,

    NotEqualTo,

    LessThan,

    LessThanOrEqualTo,

    GreaterThan,

    GreaterThanOrEqualTo

}