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.*;
class Card {
    int b;
    int c;
    public Card(int b, int c) {
	this.b = b;
	this.c = c;
    }
}
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());
	long[] a = new long[n];
	
	for(int i = 0; i<n; i++) {
	    a[i] = Long.parseLong(sc.next());
	}
	Arrays.sort(a);

	Card[] ca = new Card[m];
	for(int i = 0; i<m; i++) {
	    int b = Integer.parseInt(sc.next());
	    int c = Integer.parseInt(sc.next());
	    ca[i] = new Card(b,c);
	}

	Arrays.sort(ca, (ax,bx)-> bx.c - ax.c);

	Long[] tmp = new Long[n];
	int count = 0;
	for(int i = 0; i<m; i++) {
	    Card card = ca[i];
	    for(int j = 0; j<card.b; j++) {
		if(count==n)break;
		tmp[count] = (long)card.c;
		count++;
	    }
	    if(count==n)break;
	}
	for(int i = count; i<n; i++) {
	    tmp[i]=0L;
	}

	Arrays.sort(tmp, Comparator.reverseOrder());

	for(int i = 0; i<n; i++) {
	    if(a[i] < tmp[i]) {
		a[i] = tmp[i];
	    }else {
		break;
	    }

	}

	long total = 0;
	for(int i = 0; i<n; i++) {
	    total += a[i];
	}
	System.out.println(total);
    }
}