Problem: You need to find a binary tree of size n that satisfies a given set of c constraints. Suppose that the nodes of the unknown binary tree are labeled using a pre-order traversal starting with 1. For the i-th constraint you are given two labels, ai and bi and a direction, left or right. In case of left direction, bi is an element of the subtree rooted at ai's left child. Similarly in the case of right direction bi is an element of the subtree rooted at ai's right child.

Input

The first line of input contains two integers n and c. The next c lines contain 2 integers ai, bi (1 ≤ ai, bi ≤ n) and either "LEFT" or "RIGHT" denoting whether b is in the subtree rooted at ai's left child or in the subtree rooted at ai's right child.

The problem consists of multiple subproblems. The subproblems have different constraints on the input. You will get some score for the correct submission of the subproblem. The description of the subproblems follows.

  * In subproblem D1 (9 points), the constraints 1 ≤ n ≤ 100, 1 ≤ c ≤ 50 will hold. 
  * In subproblem D2 (8 points), the constraints 1 ≤ n ≤ 1000000, 1 ≤ c ≤ 100000 will hold. 

Output

Output will be on a single line.

Any binary tree that satisfies the constraints will be accepted. The tree's nodes should be printed out as n space separated labels representing an in-order traversal, using the pre-order numbers as labels of vertices.

If there are no trees that satisfy the constraints, print "IMPOSSIBLE" (without quotes).

Examples

Input

3 2
1 2 LEFT
1 3 RIGHT


Output

2 1 3


Input

3 2
1 2 RIGHT
1 3 LEFT


Output

IMPOSSIBLE

Note

Consider the first sample test. We need to find a tree with 3 nodes that satisfies the following two constraints. The node labeled 2 with pre-order traversal should be in the left subtree of the node labeled 1 with pre-order traversal; the node labeled 3 with pre-order traversal should be in the right subtree of the node labeled 1. There is only one tree with three nodes that satisfies these constraints and its in-order traversal is (2, 1, 3).

Pre-order is the "root – left subtree – right subtree" order. In-order is the "left subtree – root – right subtree" order.

For other information regarding in-order and pre-order, see <http://en.wikipedia.org/wiki/Tree_traversal>.

Solution (in JAVA):

Solution:
import java.io.OutputStreamWriter;
import java.io.BufferedWriter;
import java.util.Comparator;
import java.io.OutputStream;
import java.io.PrintWriter;
import java.io.Writer;
import java.io.IOException;
import java.util.Arrays;
import java.util.InputMismatchException;
import java.util.Iterator;
import java.util.NoSuchElementException;
import java.math.BigInteger;
import java.io.InputStream;

/**
 * Built using CHelper plug-in
 * Actual solution is at the top
 * @author Stanislav Pak
 */
public class Main {
	public static void main(String[] args) {
		InputStream inputStream = System.in;
		OutputStream outputStream = System.out;
		InputReader in = new InputReader(inputStream);
		OutputWriter out = new OutputWriter(outputStream);
		TaskD1 solver = new TaskD1();
		solver.solve(1, in, out);
		out.close();
	}
}

class TaskD1 {
	private static final int INF = (int) 1e8;

	class Node {
		final int id;
		Node left;
		Node right;

		Node(int id) {
			this.id = id;
		}
	}
	int[] deg;
    public void solve(int testNumber, InputReader in, OutputWriter out) {
		int n = in.readInt();
		int c = in.readInt();
		Graph graph = new Graph(n, c);
		deg = ArrayUtils.createArray(n, 0);
		for (int i = 0; i < c; ++i) {
			int from = in.readInt() - 1;
			int to = in.readInt() - 1;
			if (from >= to) {
				out.printLine("IMPOSSIBLE");
				return;
			}
			++deg[to];
			String s = in.readString();
			if ("LEFT".equals(s)) {
				graph.addWeightedEdge(from, to, 1);
			} else {
				graph.addWeightedEdge(from, to, 2);
			}
		}
		Node root = calc(graph, 0, n - 1);
		if (root == null) {
			out.printLine("IMPOSSIBLE");
		} else {
			StringBuilder sb = new StringBuilder();
			printAns(root, sb);
			out.printLine(sb);
		}
    }

	private void printAns(Node root, StringBuilder sb) {
		if (root.left != null) {
			printAns(root.left, sb);
		}
		if (sb.toString().length() > 0) {
			sb.append(" ");
		}
		sb.append(root.id + 1);
		if (root.right != null) {
			printAns(root.right, sb);
		}
	}

	private Node calc(Graph graph, int l, int r) {
		if (l > r) return null;
		Node root = new Node(l++);
		if (l > r) return root;
		int l1 = INF, r1 = -INF, l2 = INF, r2 = -INF;
		for (Edge edge : graph.outbound(root.id)) {
			int u = edge.getDestination();
			long type = edge.getWeight();
			if (type == 1) {
				l1 = Math.min(l1, u);
				r1 = Math.max(r1, u);
			} else {
				l2 = Math.min(l2, u);
				r2 = Math.max(r2, u);
			}
		}
		l1 = Math.min(l1, l);
		r2 = Math.max(r2, r);
		if (r1 >= l2) return null;
		while (true) {
			boolean extended = false;
			for (int v = l; v <= r; ++v) {
				for (Edge edge : graph.outbound(v)) {
					int to = edge.getDestination();
					if (to <= r1) {
						if (r1 < v) {
							r1 = v;
							extended = true;
						}
					}
					if (to >= l2) {
						if (v < l2) {
							l2 = v;
							extended = true;
						}
					}
				}
			}
			if (!extended) break;
		}
		if (r1 >= l2) return null;
		if (r1 == -INF && l2 == INF) {
			l1 = r1 = l;
		}
		if (r1 != -INF) {
			while (r1 + 1 < Math.min(l2, r + 1)) ++r1;
			root.left = calc(graph, l1, r1);
			if (root.left == null) return null;
		}
		if (l2 != INF) {
			while (Math.max(r1 + 1, l) < l2) --l2;
			root.right = calc(graph, l2, r2);
			if (root.right == null) return null;
		}
		return root;
	}

}

class InputReader {

	private InputStream stream;
	private byte[] buf = new byte[1024];
	private int curChar;
	private int numChars;
	private SpaceCharFilter filter;

	public InputReader(InputStream stream) {
		this.stream = stream;
	}

	public int read() {
		if (numChars == -1)
			throw new InputMismatchException();
		if (curChar >= numChars) {
			curChar = 0;
			try {
				numChars = stream.read(buf);
			} catch (IOException e) {
				throw new InputMismatchException();
			}
			if (numChars <= 0)
				return -1;
		}
		return buf[curChar++];
	}

	public int readInt() {
		int c = read();
		while (isSpaceChar(c))
			c = read();
		int sgn = 1;
		if (c == '-') {
			sgn = -1;
			c = read();
		}
		int res = 0;
		do {
			if (c < '0' || c > '9')
				throw new InputMismatchException();
			res *= 10;
			res += c - '0';
			c = read();
		} while (!isSpaceChar(c));
		return res * sgn;
	}

	public String readString() {
		int c = read();
		while (isSpaceChar(c))
			c = read();
		StringBuilder res = new StringBuilder();
		do {
			if (Character.isValidCodePoint(c))
				res.appendCodePoint(c);
			c = read();
		} while (!isSpaceChar(c));
		return res.toString();
	}

	public boolean isSpaceChar(int c) {
		if (filter != null)
			return filter.isSpaceChar(c);
		return isWhitespace(c);
	}

	public static boolean isWhitespace(int c) {
		return c == ' ' || c == '\n' || c == '\r' || c == '\t' || c == -1;
	}

	public interface SpaceCharFilter {
		public boolean isSpaceChar(int ch);
	}
}

class OutputWriter {
	private final PrintWriter writer;

	public OutputWriter(OutputStream outputStream) {
		writer = new PrintWriter(new BufferedWriter(new OutputStreamWriter(outputStream)));
	}

	public void print(Object...objects) {
		for (int i = 0; i < objects.length; i++) {
			if (i != 0)
				writer.print(' ');
			writer.print(objects[i]);
		}
	}

	public void printLine(Object...objects) {
		print(objects);
		writer.println();
	}

	public void close() {
		writer.close();
	}

}

class Graph {
	public static final int REMOVED_BIT = 0;

	protected int vertexCount;
	protected int edgeCount;

	private int[] firstOutbound;
	private int[] firstInbound;

	private Edge[] edges;
	private int[] nextInbound;
	private int[] nextOutbound;
	private int[] from;
	private int[] to;
	private long[] weight;
	public long[] capacity;
	private int[] reverseEdge;
	private int[] flags;

	public Graph(int vertexCount, int edgeCapacity) {
		this.vertexCount = vertexCount;
		firstOutbound = new int[vertexCount];
		Arrays.fill(firstOutbound, -1);

		from = new int[edgeCapacity];
		to = new int[edgeCapacity];
		nextOutbound = new int[edgeCapacity];
		flags = new int[edgeCapacity];
	}

	public int addEdge(int fromID, int toID, long weight, long capacity, int reverseEdge) {
		ensureEdgeCapacity(edgeCount + 1);
		if (firstOutbound[fromID] != -1)
			nextOutbound[edgeCount] = firstOutbound[fromID];
		else
			nextOutbound[edgeCount] = -1;
		firstOutbound[fromID] = edgeCount;
		if (firstInbound != null) {
			if (firstInbound[toID] != -1)
				nextInbound[edgeCount] = firstInbound[toID];
			else
				nextInbound[edgeCount] = -1;
			firstInbound[toID] = edgeCount;
		}
		this.from[edgeCount] = fromID;
		this.to[edgeCount] = toID;
		if (capacity != 0) {
			if (this.capacity == null)
				this.capacity = new long[from.length];
			this.capacity[edgeCount] = capacity;
		}
		if (weight != 0) {
			if (this.weight == null)
				this.weight = new long[from.length];
			this.weight[edgeCount] = weight;
		}
		if (reverseEdge != -1) {
			if (this.reverseEdge == null) {
				this.reverseEdge = new int[from.length];
				Arrays.fill(this.reverseEdge, 0, edgeCount, -1);
			}
			this.reverseEdge[edgeCount] = reverseEdge;
		}
		if (edges != null)
			edges[edgeCount] = createEdge(edgeCount);
		return edgeCount++;
	}

	protected final GraphEdge createEdge(int id) {
		return new GraphEdge(id);
	}

	public final int addFlowWeightedEdge(int from, int to, long weight, long capacity) {
		if (capacity == 0) {
			return addEdge(from, to, weight, 0, -1);
		} else {
			int lastEdgeCount = edgeCount;
			addEdge(to, from, -weight, 0, lastEdgeCount + entriesPerEdge());
			return addEdge(from, to, weight, capacity, lastEdgeCount);
		}
	}

	protected int entriesPerEdge() {
		return 1;
	}

	public final int addWeightedEdge(int from, int to, long weight) {
		return addFlowWeightedEdge(from, to, weight, 0);
	}

	public final int destination(int id) {
		return to[id];
	}

	public final long weight(int id) {
		if (weight == null)
			return 0;
		return weight[id];
	}

	protected final void initEdges() {
		if (edges == null) {
			edges = new Edge[from.length];
			for (int i = 0; i < edgeCount; i++)
				edges[i] = createEdge(i);
		}
	}

	public final boolean flag(int id, int bit) {
		return (flags[id] >> bit & 1) != 0;
	}

	public final void setFlag(int id, int bit) {
		flags[id] |= 1 << bit;
	}

	public final void removeEdge(int id) {
		setFlag(id, REMOVED_BIT);
	}

	public final boolean isRemoved(int id) {
		return flag(id, REMOVED_BIT);
	}

	public final Iterable<Edge> outbound(final int id) {
		initEdges();
		return new Iterable<Edge>() {
			public Iterator<Edge> iterator() {
				return new EdgeIterator(id, firstOutbound, nextOutbound);
			}
		};
	}

	protected void ensureEdgeCapacity(int size) {
		if (from.length < size) {
			int newSize = Math.max(size, 2 * from.length);
			if (edges != null)
				edges = resize(edges, newSize);
			from = resize(from, newSize);
			to = resize(to, newSize);
			nextOutbound = resize(nextOutbound, newSize);
			if (nextInbound != null)
				nextInbound = resize(nextInbound, newSize);
			if (weight != null)
				weight = resize(weight, newSize);
			if (capacity != null)
				capacity = resize(capacity, newSize);
			if (reverseEdge != null)
				reverseEdge = resize(reverseEdge, newSize);
			flags = resize(flags, newSize);
		}
	}

	protected final int[] resize(int[] array, int size) {
		int[] newArray = new int[size];
		System.arraycopy(array, 0, newArray, 0, array.length);
		return newArray;
	}

	private long[] resize(long[] array, int size) {
		long[] newArray = new long[size];
		System.arraycopy(array, 0, newArray, 0, array.length);
		return newArray;
	}

	private Edge[] resize(Edge[] array, int size) {
		Edge[] newArray = new Edge[size];
		System.arraycopy(array, 0, newArray, 0, array.length);
		return newArray;
	}

	protected class GraphEdge implements Edge {
		protected int id;

		protected GraphEdge(int id) {
			this.id = id;
		}

		public int getDestination() {
			return destination(id);
		}

		public long getWeight() {
			return weight(id);
		}

	}

	public class EdgeIterator implements Iterator<Edge> {
		private int edgeID;
		private final int[] next;
		private int lastID = -1;

		public EdgeIterator(int id, int[] first, int[] next) {
			this.next = next;
			edgeID = nextEdge(first[id]);
		}

		private int nextEdge(int id) {
			while (id != -1 && isRemoved(id))
				id = next[id];
			return id;
		}

		public boolean hasNext() {
			return edgeID != -1;
		}

		public Edge next() {
			if (edgeID == -1)
				throw new NoSuchElementException();
			lastID = edgeID;
			edgeID = nextEdge(next[lastID]);
			return edges[lastID];
		}

		public void remove() {
			if (lastID == -1)
				throw new IllegalStateException();
			removeEdge(lastID);
			lastID = -1;
		}
	}

}

class ArrayUtils {

	public static int[] createArray(int count, int value) {
		int[] array = new int[count];
		Arrays.fill(array, value);
		return array;
	}

}

interface Edge {
	public int getDestination();
	public long getWeight();
}