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.io.*;
import java.util.*;

class Main {
 	public static void main(String arhgs[]) throws IOException {
     	BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
      	StringTokenizer st = new StringTokenizer(br.readLine());
      	int N = Integer.parseInt(st.nextToken());
      	int M = Integer.parseInt(st.nextToken());
      	st = new StringTokenizer(br.readLine());
      	int[] arr = new int[N];
      	int i = 0;
      	while(st.hasMoreTokens()) {
         	 arr[i++] = Integer.parseInt(st.nextToken());
        }
      	Pair[] pairs = new Pair[M];
      	for(int j=0;j<M;j++) {
         	st = new StringTokenizer(br.readLine());
          	Pair p = new Pair();
          	p.setKey(Integer.parseInt(st.nextToken()));
          	p.setValue(Integer.parseInt(st.nextToken()));
          	pairs[j] = p;
        }
      	Arrays.sort(arr);
      	Arrays.sort(pairs);
      	long ans = 0;
      	for(int m=0,n=0;m<arr.length || n<pairs.length ; m++) {
			if(m == arr.length)
				break;
			Pair pp = null;
			int count = 0;
			int value = 0;
			if(n<pairs.length) {
				pp = pairs[n];
				count = pp.getKey();
				value = pp.getValue();
			}
          	if(arr[m] < value) {
              if(count > 0) {
				ans += value;
                count--;
                pp.setKey(count);
                pairs[n] = pp;
              } else {
                n++;
                m--;
              }
            }  else {
              ans += arr[m];
            }
        }
      	System.out.println(ans);
    }
}
          
class Pair implements Comparable<Pair>{
 	int key;
  	int value;
  	public void setKey(int key) {
     	this.key = key; 
    }
  	public void setValue(int value) {
     	this.value = value; 
    }
  	public int getKey() {
     	return this.key; 
    }
  	public int getValue() {
     	return this.value; 
    }
  	
  	public int compareTo(Pair pp) {
     	 return Integer.compare(pp.getValue(), this.value);
    }
}
