package program;

public class Interp {

	static class Table {
		String id; int value; Table tail;
		Table(String i, int v, Table t) { id=i; value=v; tail=t; }

		Table update(String i, Table t, int v)
		{
			return new Table(i, v, t);
		}

		int lookup(String key)
		{
			if(id == key) {
				return value;
			} else {
				return tail.lookup(key);
			}
		}
	}

	static class IntAndTable
	{
		int i; Table t;
		IntAndTable(int i, Table t) { this.i = i; this.t = t; }
		static IntAndTable interpExp(Exp e, Table t)
		{
			if(e instanceof IdExp) {
				return new IntAndTable(t.lookup(((IdExp) e).id), t);
			} else if(e instanceof NumExp) {
				return new IntAndTable(((NumExp) e).num, t);
			} else if(e instanceof OpExp) {
				IntAndTable iat1 = interpExp(((OpExp) e).left, t);
				IntAndTable iat2 = interpExp(((OpExp) e).right, iat1.t);
				switch(((OpExp) e).oper) {
					case OpExp.Plus : new IntAndTable(iat1.i + iat2.i, iat2.t);
					case OpExp.Minus : new IntAndTable(iat2.i - iat2.i, iat2.t);
					case OpExp.Times : new IntAndTable(iat2.i * iat2.i, iat2.t);
					case OpExp.Div : new IntAndTable(iat2.i / iat2.i, iat2.t);
				}
			} else if(e instanceof EseqExp) {
				Table t1 = interpStm(((EseqExp) e).stm,t);
				return interpExp(((EseqExp) e).exp,t1);
			}
			return null;
		}
	}

	static Table interpStm(Stm s, Table t)
	{
		if(s instanceof CompoundStm) {
			Table t1 = interpStm(((CompoundStm) s).stm1, t);
			return interpStm(((CompoundStm) s).stm2, t1);
		} else if(s instanceof AssignStm) {
			IntAndTable iat = IntAndTable.interpExp(((AssignStm) s).exp, t);
			return new Table(((AssignStm) s).id, iat.i, iat.t);
		} else if(s instanceof PrintStm) {
			return interpExpList(((PrintStm) s).exps,t);
		}
		return null;
	}

	static Table interpExpList(ExpList l, Table t)
	{
		if(l instanceof PairExpList) {
			IntAndTable iat = IntAndTable.interpExp(((PairExpList) l).head, t);
			System.out.println(iat.i + " ");
			return interpExpList(((PairExpList) l).tail, iat.t);
		} else if(l instanceof LastExpList) {
			IntAndTable iat = IntAndTable.interpExp(((LastExpList) l).head, t);
			System.out.println(iat.i);
			return iat.t;
		}
		return null;
	}

	static void interp(Stm s)
	{
		interpStm(s,null);
	}

	static int maxargs(Stm s)
	{
		if(s instanceof CompoundStm) {
			int s1 = maxargs(((CompoundStm) s).stm1);
			int s2 = maxargs(((CompoundStm) s).stm2);
			return s1 > s2 ? s1 : s2;
		} else if(s instanceof AssignStm) {
			return maxargs(((AssignStm) s).exp);
		} else if(s instanceof PrintStm) {
			return maxargs(((PrintStm) s).exps, 0);
		}
		return 0;
	}

	static int maxargs(Exp e)
	{
		if(e instanceof IdExp){
			return 0;
		} else if(e instanceof NumExp){
			return 0;
		} else if(e instanceof OpExp) {
			int e1 = maxargs(((OpExp) e).left);
			int e2 = maxargs(((OpExp) e).right);
			return e1 > e2 ? e1 : e2;
		} else if(e instanceof EseqExp) {
			int s = maxargs(((EseqExp) e).stm);
			int exp = maxargs(((EseqExp) e).exp);
			return s > exp ? s : exp;
		}
		return 0;
	}

	static int maxargs(ExpList l, int count)
	{
		if(l instanceof PairExpList) {
			int exp = maxargs(((PairExpList) l).head);
			int expList = maxargs(((PairExpList) l).tail, count+1);
			return exp > expList ? exp : expList;
		} else if(l instanceof LastExpList) {
			return count + 1;
		}
		return 0;
	}

	public static void main(String args[]) {
		System.out.println(maxargs(Prog.prog));
		interp(Prog.prog);
	}
}