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.io.OutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.PrintWriter;
import java.util.stream.IntStream;
import java.util.Arrays;
import java.util.stream.LongStream;
import java.util.TreeMap;
import java.util.Map;
import java.util.Map.Entry;
import java.util.Scanner;
import java.util.Comparator;

/**
 * Built using CHelper plug-in
 * Actual solution is at the top
 */
public class Main {
    public static void main(String[] args) {
        InputStream inputStream = System.in;
        OutputStream outputStream = System.out;
        Scanner in = new Scanner(inputStream);
        PrintWriter out = new PrintWriter(outputStream);
        D solver = new D();
        solver.solve(1, in, out);
        out.close();
    }

    static class D {
        public void solve(int testNumber, Scanner in, PrintWriter out) {
            int N = in.nextInt();
            int M = in.nextInt();

            int[] A = new int[N];
            for (int i = 0; i < N; i++) {
                A[i] = in.nextInt();
            }
            Arrays.sort(A);

            Map<Integer, Integer> map = new TreeMap<>(Comparator.reverseOrder());
            for (int i = 0; i < M; i++) {
                int value = in.nextInt();
                int key = in.nextInt();
                if (map.containsKey(key)) {
                    value += map.get(key);
                }
                map.put(key, value);
            }

            int index = 0;
            for (Map.Entry<Integer, Integer> entry :
                    map.entrySet()) {
                int value = entry.getValue();
                int key = entry.getKey();
                if (N <= index || key <= A[index]) {
                    break;
                }
                for (int i = 0; i < value; i++) {
                    if (N <= index || key <= A[index]) {
                        break;
                    }
                    A[index++] = key;
                }
            }

            out.println(Arrays.stream(A).asLongStream().sum());
        }

    }
}

