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.util.Arrays;
import java.util.Comparator;
import java.util.Scanner;

public class Main {

	public static void main(String[] args) {

		Scanner sc = new Scanner(System.in);
		int N = Integer.parseInt(sc.next());
		int M = Integer.parseInt(sc.next());
		Card[] cards = new Card[N + M];
		for (int i = 0; i < N; i++) {
			cards[i] = new Card(1, Integer.parseInt(sc.next()));
		}

		for (int i = N; i < M + N; i++) {
			cards[i] = new Card(Integer.parseInt(sc.next()), Integer.parseInt(sc.next()));
		}
		sc.close();

		Arrays.sort(cards, new Comparator<Card>() {
			public int compare(Card t1, Card t2) {
				return (int) (t2.num - t1.num);
			}
		});

		long ans = 0;
		long remain = N;
		for (Card card : cards) {
			if (remain <= card.count) {
				ans += remain * card.num;
				break;
			}
			ans += card.num * card.count;
			remain -= card.count;
		}

		System.out.println(ans);

	}

	static class Card {
		long num;
		int count;

		Card(int count, int num) {
			this.count = count;
			this.num = num;
		}
	}

}