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.ArrayList;
import java.util.Arrays;
import java.util.Collections;
import java.util.List;
import java.util.Scanner;

/**
 * Integer Cards
 */
public class Main {

    public static void main(String[] args) throws Exception {
        try (Scanner sc = new Scanner(System.in)) {
            int N = sc.nextInt();
            int M = sc.nextInt();

            long[] A = new long[N];
            for (int i = 0; i < N; i++) {
                A[i] = sc.nextLong();
            }

            List<BC> list = new ArrayList<>();
            for (int i = 0; i < M; i++) {
                BC bc = new BC();
                bc.B = sc.nextInt();
                bc.C = sc.nextLong();
                list.add(bc);
            }

            Arrays.sort(A);
            Collections.sort(list, (o1, o2) -> Long.compare(o2.C, o1.C));

            long sum = 0;
            long count = 0;

            for (int i = N - 1; i >= 0; i--) {
                long a = A[i];

                while (list.size() > 0 && list.get(0).C >= a) {
                    BC bc = list.get(0);

                    if (count + bc.B >= N) {
                        sum += bc.C * (N - count);
                        count = N;
                        break;
                    }

                    sum += bc.C * bc.B;
                    count += bc.B;
                    list.remove(0);
                }

                if (count == N) {
                    break;
                }

                sum += a;
                count++;

                if (count == N) {
                    break;
                }
            }

            System.out.println(sum);
        }
    }

    static class BC {

        int B;

        long C;

    }

}
