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.Math.*;
import java.math.BigInteger;

public class Main {
	public static void main(String[] args){
		Scanner sc = new Scanner(System.in);
		
		// 入力
		int n = sc.nextInt();
		int m = sc.nextInt();
		TreeMap<Integer, Integer> a = new TreeMap<Integer, Integer>();
		for(int i = 0; i < n; i++){
		    int key = sc.nextInt();
		    if(a.containsKey(key)){
		        a.put(key, a.get(key) + 1);
		    }else{
		        a.put(key, 1);
		    }
		}
	    for(int i = 0; i < m; i++){
		    int b = sc.nextInt();
		    int c = sc.nextInt();
		    if(a.containsKey(c)){
		        a.put(c, a.get(c) + b);
		    }else{
		        a.put(c, b);
		    }
		}
		
		// 計算
		long result = 0;
		int rest = n;
		while(n > 0){
		    Map.Entry<Integer, Integer> entry = a.pollLastEntry();
		    long key = entry.getKey();
		    long val = entry.getValue();
		    if(rest > val){
		        result += key * val;
		        rest -= val;
		    }else{
		        result += key * rest;
		        break;
		    }
		}
		
		// 出力
		System.out.println(result);
	}
}