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.*;
import static java.lang.Integer.*;
//import static java.lang.Long.*;
import static java.lang.System.*;

public class Main {
	public static void main(String[] args) {
		int i,j,k;
		Scanner sc = new Scanner(in);
		int n = parseInt(sc.next());
		int m = parseInt(sc.next());
		HashMap<Integer, Integer> map = new HashMap<>();
//		int[] a = new int[1000000000+1];
		int a = 0;
		for(i=0; i<n; i++) {
//			a[parseInt(sc.next())]++;
			a = parseInt(sc.next());
			if(map.containsKey(a)) {
				map.put(a, map.get(a)+1);
			} else {
				map.put(a, 1);
			}
		}
		int b;
		int c;
		for(i = 0; i < m; i++) {
			b = parseInt(sc.next());
			c = parseInt(sc.next());
			if(map.containsKey(c)) {
				map.put(c, map.get(c)+b);
			} else {
				map.put(c, b);
			}
//			a[c] += b;
		}
		sc.close();
//		out.println(Arrays.toString(a));
		Integer[] keys = map.keySet().toArray(new Integer[map.size()]);
		Arrays.sort(keys, Comparator.reverseOrder());
		int cnt = 0;
		long sum = 0;
		for(Integer ii: keys) {
			if(map.get(ii) == 0) continue;
//			out.printf("%d:%d%n", ii, map.get(ii));
			if(map.get(ii) + cnt > n ) {
				sum += (long)ii*(n-cnt);
				break;
			} else {
				sum += (long)ii*map.get(ii);
			}
			cnt += map.get(ii); 
		}
		out.println(sum);
	}
}
