You have N cards. On the i-th card, an integer A_i is written.

For each j = 1, 2, ..., M in this order, you will perform the following operation once:

Operation: Choose at most B_j cards (possibly zero). Replace the integer written on each chosen card with C_j.

Find the maximum possible sum of the integers written on the N cards after the M operations.

Constraints

* All values in input are integers.
* 1 \leq N \leq 10^5
* 1 \leq M \leq 10^5
* 1 \leq A_i, C_i \leq 10^9
* 1 \leq B_i \leq N

Input

Input is given from Standard Input in the following format:


N M
A_1 A_2 ... A_N
B_1 C_1
B_2 C_2
\vdots
B_M C_M


Output

Print the maximum possible sum of the integers written on the N cards after the M operations.

Examples

Input

3 2
5 1 4
2 3
1 5


Output

14


Input

10 3
1 8 5 7 100 4 52 33 13 5
3 10
4 30
1 4


Output

338


Input

3 2
100 100 100
3 99
3 99


Output

300


Input

11 3
1 1 1 1 1 1 1 1 1 1 1
3 1000000000
4 1000000000
3 1000000000


Output

10000000001
import java.io.IOException;
import java.io.InputStream;
import java.util.*;

public class Main {

    public static void main(String[] args) {
        FastScanner sc = new FastScanner();
         
        int n = sc.nextInt();
        int m = sc.nextInt();
        
        ArrayList<Integer> a = new ArrayList<>();
        
        for(int i=0;i<n;i++){
        	a.add(sc.nextInt());
        }
        
        Pair[] q = new Pair[m];
        
        for(int i=0;i<m;i++){
        	q[i] = new Pair(sc.nextInt(),sc.nextInt());
        }
        
        Arrays.sort(q);
        
        int ad = 0;
        int idx = m-1;
        while(ad<n && idx>=0){
        	for(int i=0;i<q[idx].a && ad<n;i++){
        		a.add(q[idx].b);
        		ad += 1;
        	}
        	idx -= 1;
        }
        
        Collections.sort(a);
        
        long ans = 0;
        int l = a.size();
        for(int i=0;i<n;i++){
        	ans += a.get(l-1-i);
        }
        
        System.out.println(ans);

    }
	
}

class Pair implements Comparable<Pair>{
	int a,b;
	
	public Pair(int a, int b){
		this.a = a;
		this.b = b;
	}
	
	@Override
	public boolean equals(Object o){
		if(o instanceof Pair){
			Pair p = (Pair) o;
			return a == p.a && b == p.b;
		}
		return super.equals(o);
	}
	
	@Override
	public int compareTo(Pair o){
		return Integer.compare(b, o.b);
	}
	
	@Override
	public int hashCode(){
		return (a<<16)+b;
	}
	
}

class FastScanner {
	private final InputStream in = System.in;
	private final byte[] buffer = new byte[1024];
	private int ptr = 0;
	private int buflen = 0;
	private boolean hasNextByte() {
		if (ptr < buflen) {
			return true;
		} else {
			ptr = 0;
			try {
				buflen = in.read(buffer);
			} catch (IOException e) {
				e.printStackTrace();
			}
			if (buflen <= 0) {
				return false;
			}
		}
		return true;
	}
	private int readByte() {
		if (hasNextByte())
			return buffer[ptr++];
		else
			return -1;
	}
	private static boolean isPrintableChar(int c) {
		return 33 <= c && c <= 126;
	}
	public boolean hasNext() {
		while (hasNextByte() && !isPrintableChar(buffer[ptr]))
			ptr++;
		return hasNextByte();
	}
	public String next() {
		if (!hasNext())
			throw new NoSuchElementException();
		StringBuilder sb = new StringBuilder();
		int b = readByte();
		while (isPrintableChar(b)) {
			sb.appendCodePoint(b);
			b = readByte();
		}
		return sb.toString();
	}
	public long nextLong() {
		if (!hasNext())
			throw new NoSuchElementException();
		long n = 0;
		boolean minus = false;
		int b = readByte();
		if (b == '-') {
			minus = true;
			b = readByte();
		}
		if (b < '0' || '9' < b) {
			throw new NumberFormatException();
		}
		while (true) {
			if ('0' <= b && b <= '9') {
				n *= 10;
				n += b - '0';
			} else if (b == -1 || !isPrintableChar(b)) {
				return minus ? -n : n;
			} else {
				throw new NumberFormatException();
			}
			b = readByte();
		}
	}
	public int nextInt() {
		long nl = nextLong();
		if (nl < Integer.MIN_VALUE || nl > Integer.MAX_VALUE)
			throw new NumberFormatException();
		return (int) nl;
	}
	public double nextDouble() {
		return Double.parseDouble(next());
	}
}