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) {
		Scanner sc = new Scanner(System.in);
		int N = sc.nextInt();
		int M = sc.nextInt();
		int[] A = new int[N];
		int[][] BC = new int[M][2];
		for(int i = 0; i < N; i++)
			A[i] = sc.nextInt();
		Arrays.sort(A);
		for(int i = 0; i < M; i++) {
			BC[i][0] = sc.nextInt();
			BC[i][1] = sc.nextInt();
		}
		Arrays.sort(BC, (x,y) -> y[1]-x[1]);
		int num = 0;
		long ans = 0;
		int s = N-1, t = 0;
		while(true) {
			if(t < M) {					
				if(A[s] >= BC[t][1]) {
					ans += A[s];
					num++;
					s--;				
				}
				else {
					if(num + BC[t][0] <= N) {
						ans += (long)BC[t][1] * BC[t][0];
						num += BC[t][0];
						t++;
					}
					else {
						ans += (long)BC[t][1] * (N - num);
						num = N;
					}
				}
			}
			else {
				ans += A[s];
				num++;
				s--;
			}
			if(num >= N)
				break;
		}
		System.out.println(ans);
	}

}