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.*;
import java.util.Map.Entry;

public class Main {
  public static void main(String[] args) {
    new Main().run();
  }

  private void run() {
    try(BufferedReader in = new BufferedReader(new InputStreamReader(System.in));
        PrintWriter out = new PrintWriter(System.out)) {

        String[] lines = in.readLine().split(" ");
        int n = Integer.parseInt(lines[0]);
        int m = Integer.parseInt(lines[1]);

        TreeMap<Long,Long> map = new TreeMap<>(Comparator.reverseOrder());

        lines = in.readLine().split(" ");
        Long b = 0L;
        for (int i = 0; i < n; i++) {
          b = Long.parseLong(lines[i]);
          if(map.containsKey(b)) map.put(b, map.get(b) + 1);
          else  map.put(b, 1L);
        }

        Long c = 0L;
        for (int i = 0; i < m; i++) {
          lines = in.readLine().split(" ");
          b = Long.parseLong(lines[0]);
          c = Long.parseLong(lines[1]);
          if(map.containsKey(c)) map.put(c, map.get(c) + b);
          else map.put(c, b);
        }

        Long N = Long.valueOf(n);
        Long ans = 0L;
        Entry<Long, Long> entry;
        Long k, v;
        Iterator<Entry<Long, Long>> ite = map.entrySet().iterator();
        for(Long cnt = 0L; cnt < N; cnt += v) {
          entry = ite.next();
          k = entry.getKey();
          v = entry.getValue();
          if(cnt + v < N) ans += k * v;
          else ans += k * (n - cnt);
        }

        out.println(ans);
        out.flush();
    }
    catch(IOException e) {
      System.err.println(e);
    }
  }
}