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[]) {
    int rep = 1;
    if( args.length > 0 ) { rep = Integer.parseInt(args[0]); }
    (new Main()).__solve(rep);
  }

  void __solve(int rep) {

    try (
      Scanner cin = new Scanner(System.in);
    ) {

      for( int i = 0; i < rep; ++i ) {
        __solve(cin);
      }

    }

  }

  void __solve(Scanner cin) {
	  
	  int N = cin.nextInt();
	  int K = cin.nextInt();
	  
	  int arr[] = new int[N];
	  for( int i = 0; i < N; ++i ) {
		  arr[i] = cin.nextInt();
	  }
	  Arrays.sort(arr);
	  int val[][] = new int[K][2];
	  for( int i = 0; i < K; ++i ) {
		  val[i][0] = cin.nextInt();
		  val[i][1] = cin.nextInt();
	  }
	  Arrays.sort(val, new Comparator<int[]>() {
		  public int compare(int a[], int b[]) {
			  if( a[1] > b[1] ) { return -1; }
			  if( a[1] < b[1] ) { return 1; }
			  return 0;
		  }
	  });

	  long sumRest[] = new long[N + 1];
	  for( int i = N - 1; i >= 0; --i ) {
		  sumRest[i] = sumRest[i + 1] + arr[i];
	  }
	  
	  long max = sumRest[0];
	  int L = 0;
	  long sum = 0;
	  for( int i = 0; i < K; ++i ) {
		  for( int j = 0; j < val[i][0]; ++j ) {
			  if( L == N ) { break; }
			  ++L;
			  sum += val[i][1];
			  max = Math.max(max, sum + sumRest[L]);
		  }
	  }

	  System.out.println(max);

  }

}
