import java.io.*;
import java.util.*;

class D
{
	private static final Scanner cin = new Scanner(System.in);

	public static void main(String[] args)
	{
		while(true)
		{
			int n = cin.nextInt();
			if(n == 0) { break; }

			Storage storage = new Storage();

			for(int i = 0; i < n; i++)
			{
				String cmd = cin.next("[WDR]");

				switch(cmd.charAt(0))
				{
					case 'W':
						storage.create(cin.nextInt(), cin.nextInt());
						break;
					case 'D':
						storage.delete(cin.nextInt());
						break;
					case 'R':
						System.out.println(storage.refer(cin.nextInt()));
						break;
				}

//				storage.dump();
			}

			System.out.println();
		}
	}

	private static class Storage
	{
		private List<Fragment> data;

		public static final int FREE = -1;

		public Storage()
		{
			data = new LinkedList<Fragment>();
			data.add(new Fragment(0, Integer.MAX_VALUE, FREE));
		}

		public void dump()
		{
			System.err.println("--------");

			for(Fragment f : data)
			{
				System.err.println(f.addr + " " + f.size + " " + f.file);
			}
		}

		public void create(int file, int size)
		{
			verify(file, 0, "file");
			verify(size, 1, "size");

			ListIterator<Fragment> i = data.listIterator();

			while(size > 0)
			{
				Fragment f = i.next();

				if(f.file != FREE)
				{
					continue;
				}

				if(f.size <= size)
				{
					f.file = file;
					size -= f.size;
				}
				else
				{
					i.previous();
					i.add(new Fragment(f.addr, size, file));
					f.addr += size;
					f.size -= size;
					break;
				}
			}
		}

		public void delete(int file)
		{
			verify(file, 0, "file");

			Iterator<Fragment> i = data.iterator();

			while(i.hasNext())
			{
				Fragment f = i.next();

				if(f.file == file)
				{
					f.file = FREE;
				}
			}
		}

		public int refer(int addr)
		{
			verify(addr, 0, "addr");

			Iterator<Fragment> i = data.iterator();

			while(true)
			{
				Fragment f = i.next();

				if(f.addr + f.size > addr)
				{
					return f.file;
				}
			}
		}

		private static void verify(int value, int limit, String name)
		{
			if(value < limit)
			{
				throw new IllegalArgumentException("Illegal " + name + ": " + value);
			}
		}
	}

	private static class Fragment
	{
		public int addr;
		public int size;
		public int file;

		public Fragment(int addr, int size, int file)
		{
			this.addr = addr;
			this.size = size;
			this.file = file;
		}
	}
}