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.*;

public class Main{
    
    public static void main(String[] arg){

        Scanner scan =new Scanner(System.in);

        int n=Integer.parseInt(scan.next());
        int m=Integer.parseInt(scan.next());

        long[] A=new long[n];

        for(int i=0;i<n;i++){
            A[i]=scan.nextLong();
         
        }

        int i,j,k;
        
        BandC[] BC=new BandC[m];
        SortBandC srt=new SortBandC();

        for(i=0;i<m;i++){

            BC[i]=new BandC(Integer.parseInt(scan.next()), 
                Integer.parseInt(scan.next()));
        }

        Arrays.sort(BC, srt);

        int[] D=new int[n];
        int count=0;
        for(k=0;k<m;k++){
            for(i=0;i<BC[k].b;i++){
                if(count>=n) break;
                D[count]=BC[k].c;
                count++;
                

            }
        }

        Arrays.sort(A);


        for(i=0;i<n;i++){
            if(A[i]<=D[i]) A[i]=D[i];
        }
        

        long sum = 0;
        for(long d : A){
        sum += d;
        }
        System.out.print(sum);
        
        
     
    }

    static class BandC{
        int b,c;

        BandC(int b,int c){
            this.b=b;
            this.c=c;
        }
    }

    static class SortBandC implements Comparator<BandC>{
        public int compare(BandC bc1,BandC bc2){
            return bc2.c-bc1.c;
        }
    }

}

