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.*;
import java.util.*;

public class Main {
    public static void main(String[] args) {
        MyScanner sc = new MyScanner();

        int n = sc.nextInt();
        int m = sc.nextInt();

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

        Map<Long, Integer> map = new TreeMap<>();
        for (int i = 0; i < m; i++) {
            int b = sc.nextInt();
            long c = sc.nextLong();
            if (map.containsKey(c))
                map.put(c, map.get(c) + b);
            else
                map.put(c, b);
        }

        Arrays.sort(a);

        long ans = 0;
        Object[] keys = map.keySet().toArray();
        int keysIndex = keys.length-1;
        for (int i = 0; i < n; i++) {
            long key = -1;
            if (keysIndex >= 0)
                key = (long)keys[keysIndex];

            if (a[i] < key) {
                ans += key;
                map.put(key, map.get(key)-1);
            } else {
                ans += a[i];
            }

            if (key >= 0 && map.get(key) <= 0)
                keysIndex = Math.max(-1, keysIndex-1);
        }

        System.out.println(ans);
    }

    static class MyScanner {
        BufferedReader reader = new BufferedReader(new InputStreamReader(System.in), 1 << 15);
        StringTokenizer tokenizer;

        String next() {
            try {
                while (tokenizer == null || !tokenizer.hasMoreTokens()) {
                    tokenizer = new StringTokenizer(reader.readLine());
                }
            } catch (IOException ignored) {
            }
            return tokenizer.nextToken();
        }

        int nextInt() {
            return Integer.parseInt(next());
        }

        long nextLong() {
            return Long.parseLong(next());
        }
    }
}