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 sc = new Scanner(System.in);
		int n=sc.nextInt();
		int m=sc.nextInt();
		int table[][] = new int[n+m][2];
		for(int i=0;i<n;i++) {
			table[i][0]=sc.nextInt();
			table[i][1]=1;
		}
		for(int i=0;i<m;i++) {
			table[n+i][1]=sc.nextInt();
			table[n+i][0]=sc.nextInt();
		}
		
		Arrays.sort(table, (a, b) -> Integer.compare(a[0], b[0]));
		
		long backet=n;
		int number=n+m-1;
		long sum=0;
		long t0, t1;
		while(backet>0) {
			t0=table[number][0];
			t1=table[number][1];
			sum+=t0 * min(t1, backet);
			backet-=t1;
			number--;
		}
		
		System.out.println(sum);
		
	}
	
	public static long min(long a, long b) {
		if(a<b)
			return a;
		else
			return b;
	}

}