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.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.util.Collections;
import java.util.PriorityQueue;

public class Main {

	public static void main(String[] args) throws IOException {
		BufferedReader br = new BufferedReader(new InputStreamReader(System.in));

		String str[] = br.readLine().split(" ");

		int n = Integer.parseInt(str[0]);
		int m = Integer.parseInt(str[1]);

		str = br.readLine().split(" ");

		PriorityQueue<Pair> pq = new PriorityQueue<>(Collections.reverseOrder());

		for (int i = 0; i < n; i++) {
			long a = Long.parseLong(str[i]);
			pq.add(new Pair(1, a));
		}

		for (int i = 0; i < m; i++) {
			str = br.readLine().split(" ");
			int b = Integer.parseInt(str[0]);
			long c = Long.parseLong(str[1]);

			pq.add(new Pair(b, c));
		}

		long ans = 0;
		long count = 0;

		for (int i = 0; i < n; i++) {
			Pair p = pq.poll();
			if (count + p.size <= n) {
				ans += p.size * p.value;
				count += p.size;
			} else {
				ans += (n - count) * p.value;
				count = n;
				break;
			}
		}

		System.out.println(ans);
	}
}

class Pair implements Comparable<Pair> {
	int size;
	long value;

	public Pair(int size, long value) {
		this.size = size;
		this.value = value;
	}

	@Override
	public int compareTo(Pair p) {
		return Long.compare(this.value, p.value);
	}
}