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.Comparator;
import java.util.Scanner;

class Solver {
	static final Solver INSTANCE = new Solver();

	void solve(Scanner sc) {
		int N = sc.nextInt();
		int M = sc.nextInt();
		int[] A = new int[N];
		for (int i = 0; i < N; i++) {
			A[i] = sc.nextInt();
		}
		Arrays.sort(A);
		class fill implements Comparable<fill> {
			final int count;
			final int value;

			fill(int count, int value) {
				this.count = count;
				this.value = value;
			}

			@Override
			public int compareTo(fill o) {
				return Comparator.<fill>comparingInt(f -> f.value).compare(this, o);
			}
		}
		fill[] fillers = new fill[M];
		for (int i = 0; i < M; i++) {
			fillers[i] = new fill(sc.nextInt(), sc.nextInt());
		}
		Arrays.sort(fillers, Comparator.reverseOrder());

		long sum = 0;
		int i = 0;
		f:
		for (fill filler : fillers) {
			for (int j = 0; j < filler.count; j++) {
				if (i >= A.length || A[i] > filler.value) {
					break f;
				}
				sum += filler.value;
				i++;
			}
		}
		for (; i < A.length; i++) {
			sum += A[i];
		}
		System.out.println(sum);
	}
}

class Main {
	public static void main(String... args) {
		Scanner in = new Scanner(System.in);

		Solver.INSTANCE.solve(in);

		in.close();
	}
}