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.*;
public class Main {
	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		int num = sc.nextInt();
		int count = sc.nextInt();
		long integers[] = new long[num];
		for(int i = 0; i < num; i ++) {
			integers[i] = sc.nextLong();
		}
		Arrays.sort(integers);

		long change[][] = new long[count][2];
		for(int i = 0; i < count; i ++) {
			change[i][0] = sc.nextLong();
			change[i][1] = sc.nextLong();
		}
		Arrays.sort(change, (a, b) -> Long.compare(b[1], a[1]));
		int crtIndex = 0;
		int crtCount = 0;
		for(int i = 0; i < num; i ++) {
			if(change[crtIndex][1] < integers[i]) { break; }
			integers[i] = change[crtIndex][1];
			crtCount ++;
			if(crtCount >= change[crtIndex][0]) { crtCount = 0; crtIndex ++; }
			if(crtIndex >= count) { break; }
		}

		long ans = 0;
		for(int i = 0; i < num; i ++) {
			ans += integers[i];
		}

		System.out.println(ans);
	}
}