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.*;

public class Main {
    public static void main(String[] args) throws Exception {
        Scanner sc = new Scanner(System.in);
        
        int N = sc.nextInt();
        int M = sc.nextInt();
        
        int[] A = new int[N];
        for(int i= 0; i < N; i++){
            A[i] = sc.nextInt();
        }
        Arrays.sort(A);
        
        Data[] BC = new Data[M];
        for(int i= 0; i < M; i++) {
            int B = sc.nextInt();
            int C = sc.nextInt();
            BC[i] = new Data(B, C);
        }
        Arrays.sort(BC, new Comparator<Data>() {
            public int compare(Data d1, Data d2) {
                return d2.getB() - d1.getB();
            }
        });

        
        int cnt = 0;
        int A_cnt = 0;
        label: while(cnt < M){
            int C = BC[cnt].getB();
            for(int i = 0; i < BC[cnt].getA(); i++){
                if(A[A_cnt] < C){
                    A[A_cnt] = C;
                    A_cnt ++;
                    if(A_cnt >= N){
                        break label;
                    }
                } else{
                    break label;
                }
            }
            cnt ++;
        }
        
        long ans = 0;
        for(int i = 0; i < N; i++){
            ans += A[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;
    }
}