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.Scanner;

public class Main{

	public static void main(String[] args) {
		Scanner scn = new Scanner(System.in);
		int N = scn.nextInt();
		int M = scn.nextInt();
		long[] A = new long[N];
		for (int i = 0; i < N; i++) {
			A[i] = scn.nextLong();
		}
		Card[] C = new Card[M];
		for (int i = 0; i < M; i++) {
			int B = scn.nextInt();
			long ci = scn.nextLong();
			C[i] = new Card(B, ci);
		}
		Arrays.sort(A);
		Arrays.sort(C);

		long[] buf = new long[N];
		int nowS = 0;
		for (int i = M - 1; i >= 0 && nowS < N; i--) {
			Card c = C[i];
			Arrays.fill(buf, nowS, Math.min(nowS + c.num, N), c.C);
			nowS += c.num;
		}
		Arrays.sort(buf);
		long ans = 0;
		int a = N - 1, b = N - 1;
		for (int i = 0; i < N; i++) {
			if (A[a] > buf[b]) {
				ans += A[a];
				a--;
			} else {
				ans += buf[b];
				b--;
			}
		}
		System.out.println(ans);
	}
}

class Card implements Comparable<Card> {
	int num;
	long C;

	public Card(int b, long c) {
		this.num = b;
		this.C = c;
	}

	@Override
	public int compareTo(Card o) {
		if (this.C > o.C) {
			return 1;
		}
		if (this.C < o.C) {
			return -1;
		}
		return 0;
	}

}
