// No.2757 Pin Game
import java.util.*;

public class Main {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        int n = sc.nextInt();
        int m = sc.nextInt();
        int[] pins = new int[n];
        for (int i = 0; i < n; i++) {
            pins[i] = sc.nextInt();
        }

        int score = 0;
        for (int i = 0; i < m; i++) {
            int x = sc.nextInt();
            int y = sc.nextInt();
            if (pins[x - 1] > 0) {
                score += y;
                pins[x - 1]--;
            }
        }

        System.out.println(score);
    }
}