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 java.util.Arrays;
import java.util.Comparator;
public class Main {    
	public static void main(String[] args){
		Scanner sc = new Scanner(System.in);
        int n = sc.nextInt();        
		int a = sc.nextInt();
        int [] s = new int [n];
        for(int i=0;i<n;i++){s[i]=sc.nextInt();}
        Arrays.sort(s);
        long ans = 0;       
        Data [] d = new Data [a];
        for(int i=0;i<a;i++){int B = sc.nextInt();
                             int C = sc.nextInt();
                             d[i] = new Data(B,C);                            
                            }
        Arrays.sort(d, new Comparator<Data>() {
            public int compare(Data d1, Data d2) {
                return d1.getB() - d2.getB();
            }
        }); 
        int b = a-1;
        int count = 0;
        for(int i=0;i<n;i++){if(b>=0 && d[b].getB()>s[i]){s[i]=d[b].getB();
                                                          count++;                                                 
                                                          if(count==d[b].getA())
                                                          {b--;count=0;}
                                                         }else{break;}
                  }        
		for(int i=0;i<n;i++){ans+=s[i];}
        System.out.println(ans);
	}
}
class Data{
    private int a;
    private int b;
    public Data(int a, int b) {
        this.a = a;
        this.b = b;
    }
    public int getA() {
        return a;
    }
    public int getB() {
        return b;
    }
}