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.*;
import java.math.RoundingMode;
import java.math.BigDecimal;
 
 
 
public class Main{
	 public static void main(String[] args){
		Scanner sc = new Scanner(System.in);
		int n = sc.nextInt();
		int m = sc.nextInt();
		int a[] = new int[n];
		for(int i = 0; i < n; i++) {
			a[i] = sc.nextInt();
		}
		int bc[][] = new int[m][2];
		for(int i = 0; i < m; i++) {
			bc[i][0] = sc.nextInt();
			bc[i][1] = sc.nextInt();
		}
		Arrays.sort(a);
		Arrays.sort(bc, (ab, b)->Integer.compare(ab[1], b[1]));
		int now = 0;
		for(int i = m-1; i >= 0; i--) {
			for(int j = now; j < n; j++) {
				if(a[j]<bc[i][1]){
					a[j] = bc[i][1];
					bc[i][0]--;
					now++;
				}
				if(bc[i][0]<1) {
					break;
				}
			}
			if(bc[i][0]>0) {
				break;
			}
		}
		long ans = 0;
		for(int i = 0; i < n; i++) {
			ans+=a[i];
		}
		System.out.println(ans);
	 }
}