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.Map;
import java.util.Scanner;
import java.util.TreeMap;


public class Main {
	public static void main(String[] args) throws Exception {
		try(Scanner sc = new Scanner(System.in)) {
			int n = sc.nextInt();
			int m = sc.nextInt();
			long[] a = new long[n];
			for(int i=0; i<n; i++) {
				a[i] = sc.nextLong();
			}
			Arrays.sort(a);
			Map<Integer, Integer> map = new TreeMap<>(Comparator.reverseOrder());
			for(int i=0; i<m; i++) {
				int s = sc.nextInt();
				int t = sc.nextInt();
				if(map.get(t)!=null)	s+=map.get(t);
				map.put(t, s);
			}
			long ans = 0;
			int now = 0;
			for(Integer key:map.keySet()) {
				int dis = Math.min(now+map.get(key), n);
				for(int i=now; i<dis; i++) {
					if(a[i]<key) {
						a[i] = key;
					}
				}
				now = dis;
			}
			for(int i=0; i<n; i++) {
				ans += a[i];
			}
			System.out.println(ans);
		}
	}

}