Problem: You have recently fallen through a hole and, after several hours of unconsciousness, have realized you are in an underground city. On one of your regular, daily walks through the unknown, you have encountered two unusually looking skeletons called Sanz and P’pairus, who decided to accompany you and give you some puzzles for seemingly unknown reasons.

One day, Sanz has created a crossword for you. Not any kind of crossword, but a 1D crossword! You are given m words and a string of length n. You are also given an array p, which designates how much each word is worth — the i-th word is worth pi points. Whenever you find one of the m words in the string, you are given the corresponding number of points. Each position in the crossword can be used at most x times. A certain word can be counted at different places, but you cannot count the same appearance of a word multiple times. If a word is a substring of another word, you can count them both (presuming you haven’t used the positions more than x times).

In order to solve the puzzle, you need to tell Sanz what’s the maximum achievable number of points in the crossword. There is no need to cover all postions, just get the maximal score! Crossword and words contain only lowercase English letters.

Input

The first line of the input contains a single integer n (1 ≤ n ≤ 500) — the length of the crossword. The second line contains the crossword string. The third line contains a single integer m (1 ≤ m ≤ 100) — the number of given words, and next m lines contain description of words: each line will have a string representing a non-empty word (its length doesn't exceed the length of the crossword) and integer pi (0 ≤ pi ≤ 100). Last line of the input will contain x (1 ≤ x ≤ 100) — maximum number of times a position in crossword can be used.

Output

Output single integer — maximum number of points you can get.

Example

Input

6
abacba
2
aba 6
ba 3
3


Output

12

Note

For example, with the string "abacba", words "aba" (6 points) and "ba" (3 points), and x = 3, you can get at most 12 points - the word "aba" appears once ("abacba"), while "ba" appears two times ("abacba"). Note that for x = 1, you could get at most 9 points, since you wouldn’t be able to count both "aba" and the first appearance of "ba".

Solution (in JAVA):

Solution:
//package bubblecup9f;
import java.io.ByteArrayInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.PrintWriter;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.InputMismatchException;
import java.util.List;

public class G {
	InputStream is;
	PrintWriter out;
	String INPUT = "";
	
	void solve()
	{
		int n = ni();
		char[] s = ns(n);
		List<Edge> es = new ArrayList<>();
		int m = ni();
		int[] ps = new int[m];
		char[][] qs = new char[m][];
		for(int i = 0;i < m;i++){
			qs[i] = ns().toCharArray();
			ps[i] = ni();
		}
		int x = ni();
		
		for(int i = 0;i < n;i++){
			es.add(new Edge(i, i+1, x, 20000));
		}
		for(int i = 0;i < m;i++){
			inner:
			for(int j = 0;j+qs[i].length-1 < n;j++){
				for(int k = 0;k < qs[i].length;k++){
					if(s[j+k] != qs[i][k])continue inner;
				}
				es.add(new Edge(j, j+qs[i].length, 1, 20000*qs[i].length-ps[i]));
			}
		}
		long F = solveMinCostFlow(compileWD(n+1, es), 0, n, x);
		out.println(20000L*n*x-F);
	}
	
	public static class Edge
	{
		public int from, to;
		public int capacity;
		public int cost;
		public int flow;
		public Edge complement;
		// public int iniflow;
		
		public Edge(int from, int to, int capacity, int cost) {
			this.from = from;
			this.to = to;
			this.capacity = capacity;
			this.cost = cost;
		}
	}
	
	public static Edge[][] compileWD(int n, List<Edge> edges)
	{
		Edge[][] g = new Edge[n][];
		// cloning
		for(int i = edges.size()-1;i >= 0;i--){
			Edge origin = edges.get(i);
			Edge clone = new Edge(origin.to, origin.from, origin.capacity, -origin.cost);
			clone.flow = origin.capacity;
			clone.complement = origin;
			origin.complement = clone;
			edges.add(clone);
		}
		
		int[] p = new int[n];
		for(Edge e : edges)p[e.from]++;
		for(int i = 0;i < n;i++)g[i] = new Edge[p[i]];
		for(Edge e : edges)g[e.from][--p[e.from]] = e;
		return g;
	}

	// NOT VERIFIED
	public static Edge[][] compileWU(int n, List<Edge> edges)
	{
		Edge[][] g = new Edge[n][];
		// cloning
		for(int i = edges.size()-1;i >= 0;i--){
			Edge origin = edges.get(i);
			Edge back = new Edge(origin.to, origin.from, origin.capacity, origin.cost);
			edges.add(back);
		}
		for(int i = edges.size()-1;i >= 0;i--){
			Edge origin = edges.get(i);
			Edge clone = new Edge(origin.to, origin.from, origin.capacity, -origin.cost);
			clone.flow = origin.capacity;
			clone.complement = origin;
			origin.complement = clone;
			edges.add(clone);
		}
		
		int[] p = new int[n];
		for(Edge e : edges)p[e.from]++;
		for(int i = 0;i < n;i++)g[i] = new Edge[p[i]];
		for(Edge e : edges)g[e.from][--p[e.from]] = e;
		return g;
	}	

	public static class MinHeap {
		public int[] a;
		public int[] map;
		public int[] imap;
		public int n;
		public int pos;
		public static int INF = Integer.MAX_VALUE;
		
		public MinHeap(int m)
		{
			n = m+2;
			a = new int[n];
			map = new int[n];
			imap = new int[n];
			Arrays.fill(a, INF);
			Arrays.fill(map, -1);
			Arrays.fill(imap, -1);
			pos = 1;
		}
		
		public int add(int ind, int x)
		{
			int ret = imap[ind];
			if(imap[ind] < 0){
				a[pos] = x; map[pos] = ind; imap[ind] = pos;
				pos++;
				up(pos-1);
			}
			return ret != -1 ? a[ret] : x;
		}
		
		public int update(int ind, int x)
		{
			int ret = imap[ind];
			if(imap[ind] < 0){
				a[pos] = x; map[pos] = ind; imap[ind] = pos;
				pos++;
				up(pos-1);
			}else{
				int o = a[ret];
				a[ret] = x;
				up(ret);
				down(ret);
//				if(a[ret] > o){
//					up(ret);
//				}else{
//					down(ret);
//				}
			}
			return x;
		}
		
		public int remove(int ind)
		{
			if(pos == 1)return INF;
			if(imap[ind] == -1)return INF;
			
			pos--;
			int rem = imap[ind];
			int ret = a[rem];
			map[rem] = map[pos];
			imap[map[pos]] = rem;
			imap[ind] = -1;
			a[rem] = a[pos];
			a[pos] = INF;
			map[pos] = -1;
			
			up(rem);
			down(rem);
			return ret;
		}
		
		public int min() { return a[1]; }
		public int argmin() { return map[1]; }
		public int size() {	return pos-1; }
		
		private void up(int cur)
		{
			for(int c = cur, p = c>>>1;p >= 1 && a[p] > a[c];c>>>=1, p>>>=1){
				int d = a[p]; a[p] = a[c]; a[c] = d;
				int e = imap[map[p]]; imap[map[p]] = imap[map[c]]; imap[map[c]] = e;
				e = map[p]; map[p] = map[c]; map[c] = e;
			}
		}
		
		private void down(int cur)
		{
			for(int c = cur;2*c < pos;){
				int b = a[2*c] < a[2*c+1] ? 2*c : 2*c+1;
				if(a[b] < a[c]){
					int d = a[c]; a[c] = a[b]; a[b] = d;
					int e = imap[map[c]]; imap[map[c]] = imap[map[b]]; imap[map[b]] = e;
					e = map[c]; map[c] = map[b]; map[b] = e;
					c = b;
				}else{
					break;
				}
			}
		}
	}
	
	public static long solveMinCostFlow(Edge[][] g, int source, int sink, long all)
	{
		int n = g.length;
		long mincost = 0;
		int[] potential = new int[n];
		
		final int[] d = new int[n];
		MinHeap q = new MinHeap(n);
		while(all > 0){
			// shortest path src->sink
			Edge[] inedge = new Edge[n];
			Arrays.fill(d, Integer.MAX_VALUE / 2);
			d[source] = 0;
			q.add(source, 0);
			while(q.size() > 0){
				int cur = q.argmin();
				q.remove(cur);
				for(Edge ne : g[cur]){
					if(ne.capacity - ne.flow > 0){
						int nd = d[cur] + ne.cost + potential[cur] - potential[ne.to];
						if(d[ne.to] > nd){
							inedge[ne.to] = ne;
							d[ne.to] = nd;
							q.update(ne.to, nd);
						}
					}
				}
			}
			
			if(inedge[sink] == null)break;
			
			long minflow = all;
			long sumcost = 0;
			for(Edge e = inedge[sink];e != null;e = inedge[e.from]){
				if(e.capacity - e.flow < minflow)minflow = e.capacity - e.flow;
				sumcost += e.cost;
			}
			mincost += minflow * sumcost;
			for(Edge e = inedge[sink];e != null;e = inedge[e.from]){
				e.flow += minflow;
				e.complement.flow -= minflow;
			}
			
			all -= minflow;
			for(int i = 0;i < n;i++){
				potential[i] += d[i];
			}
		}
		return mincost;
	}

	
	void run() throws Exception
	{
		is = oj ? System.in : new ByteArrayInputStream(INPUT.getBytes());
		out = new PrintWriter(System.out);
		
		long s = System.currentTimeMillis();
		solve();
		out.flush();
		tr(System.currentTimeMillis()-s+"ms");
	}
	
	public static void main(String[] args) throws Exception { new G().run(); }
	
	private byte[] inbuf = new byte[1024];
	private int lenbuf = 0, ptrbuf = 0;
	
	private int readByte()
	{
		if(lenbuf == -1)throw new InputMismatchException();
		if(ptrbuf >= lenbuf){
			ptrbuf = 0;
			try { lenbuf = is.read(inbuf); } catch (IOException e) { throw new InputMismatchException(); }
			if(lenbuf <= 0)return -1;
		}
		return inbuf[ptrbuf++];
	}
	
	private boolean isSpaceChar(int c) { return !(c >= 33 && c <= 126); }
	private int skip() { int b; while((b = readByte()) != -1 && isSpaceChar(b)); return b; }
	
	private double nd() { return Double.parseDouble(ns()); }
	private char nc() { return (char)skip(); }
	
	private String ns()
	{
		int b = skip();
		StringBuilder sb = new StringBuilder();
		while(!(isSpaceChar(b))){ // when nextLine, (isSpaceChar(b) && b != ' ')
			sb.appendCodePoint(b);
			b = readByte();
		}
		return sb.toString();
	}
	
	private char[] ns(int n)
	{
		char[] buf = new char[n];
		int b = skip(), p = 0;
		while(p < n && !(isSpaceChar(b))){
			buf[p++] = (char)b;
			b = readByte();
		}
		return n == p ? buf : Arrays.copyOf(buf, p);
	}
	
	private char[][] nm(int n, int m)
	{
		char[][] map = new char[n][];
		for(int i = 0;i < n;i++)map[i] = ns(m);
		return map;
	}
	
	private int[] na(int n)
	{
		int[] a = new int[n];
		for(int i = 0;i < n;i++)a[i] = ni();
		return a;
	}
	
	private int ni()
	{
		int num = 0, b;
		boolean minus = false;
		while((b = readByte()) != -1 && !((b >= '0' && b <= '9') || b == '-'));
		if(b == '-'){
			minus = true;
			b = readByte();
		}
		
		while(true){
			if(b >= '0' && b <= '9'){
				num = num * 10 + (b - '0');
			}else{
				return minus ? -num : num;
			}
			b = readByte();
		}
	}
	
	private long nl()
	{
		long num = 0;
		int b;
		boolean minus = false;
		while((b = readByte()) != -1 && !((b >= '0' && b <= '9') || b == '-'));
		if(b == '-'){
			minus = true;
			b = readByte();
		}
		
		while(true){
			if(b >= '0' && b <= '9'){
				num = num * 10 + (b - '0');
			}else{
				return minus ? -num : num;
			}
			b = readByte();
		}
	}
	
	private boolean oj = System.getProperty("ONLINE_JUDGE") != null;
	private void tr(Object... o) { if(!oj)System.out.println(Arrays.deepToString(o)); }
}