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.Arrays;
import java.util.Scanner;

public class Main {

	private void solve() {
		
		Scanner in = new Scanner(System.in);
		int N = in.nextInt();
		int M = in.nextInt();
		Operation[] operations = new Operation[N+M];
		for(int i=0;i<N;i++) {
			int A = in.nextInt();
			operations[i] = new Operation(1,A);
		}
		for(int j=N;j<N+M;j++) {
			int B = in.nextInt();
			int C = in.nextInt();
			operations[j] = new Operation(B,C);
		}
		Arrays.sort(operations);
		long ans = 0;
		int card_num = N;
		int k = 0;
		while(card_num>0) {
			if(operations[k].B > card_num) operations[k].B = card_num;
			ans += 1.0 * operations[k].C * operations[k].B;
			card_num -= operations[k].B;
			k++;
		}
		System.out.println(ans);
	}
	
	public static void main(String[] args) {
		new Main().solve();
	}
	
	public class Operation implements Comparable<Operation>{
		public int B;
		public int C;
		
		public Operation(int B, int C) {
			this.B = B;
			this.C = C;
		}
		
		@Override
		public int compareTo(Operation other) {
			return -Integer.compare(C, other.C);
		}
	}
}