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 n = Integer.parseInt(sc.next());
        int m = Integer.parseInt(sc.next());
        int[] a = new int[n];
        for (int i = 0; i < n; i++) {
            a[i] = Integer.parseInt(sc.next());
        }
        Arrays.sort(a);

        List<Pair> pairs = new ArrayList<>();
        for (int i = 0; i < m; i++) {
            pairs.add(new Pair(Integer.parseInt(sc.next()), Integer.parseInt(sc.next())));
        }
        Collections.sort(pairs);

        int[] d = new int[n];
        int index = 0;
        long sum = 0;
        for (Pair p : pairs) {
            int b = p.b;
            int c = p.c;
            for (int j = 0; j < b; j++) {
                d[index] = c;
                sum += c;
                index++;
                if (index >= n) {
                    break;
                }
            }
            if (index >= n) {
                break;
            }
        }

        for (int i = 0; i < n; i++) {
            long tmp = sum - d[n - 1 - i] + a[n - 1 - i];
            if (sum > tmp) {
                break;
            }
            sum = tmp;
        }

        System.out.println(sum);

    }

    public static class Pair implements Comparable<Pair> {
        int b;
        int c;

        public Pair(int b, int c) {
            this.b = b;
            this.c = c;
        }

        @Override
        public int compareTo(Pair o) {
            return o.c - this.c;
        }
    }
}
