package pickpocket;

import java.io.BufferedReader;
import java.io.File;
import java.io.IOException;
import java.io.InputStreamReader;
import java.util.ArrayList;
import java.util.Collections;
import java.util.Comparator;
import java.util.List;

class SortbyEfficiancy implements Comparator<int[]> {


	@Override
	public int compare(int[] o1, int[] o2) {
		// TODO Auto-generated method stub
		return ((-1)*(o1[1]/o1[0]) - (o2[1]/o2[0]));
	}

}

public class pickpockets {
	public static void main(String[] args) throws IOException {
		String tmp;
		String tmpstr[] = new String[2];
		int days = 0, sum = 0;
		List<int[]> operations = new ArrayList<int[]>();
		BufferedReader reader = new BufferedReader(
				new InputStreamReader(System.in));

		tmp = reader.readLine();
		tmpstr = tmp.split(" ", 2);
		days = Integer.parseInt(tmpstr[0]);
		int numOfCleanStores [] = new int  [days];
		tmp = reader.readLine();
		tmpstr = tmp.split(" ", -1);
		for(int i = 0; i < days; i++) {
			numOfCleanStores[i] = Integer.parseInt(tmpstr[i]);
		}
		while((tmp = reader.readLine()) != null) {
			tmpstr = tmp.split(" ");
			int [] tmpint = {Integer.parseInt(tmpstr[0]), Integer.parseInt(tmpstr[1])};
			operations.add(tmpint);
		}

		Collections.sort(operations, new SortbyEfficiancy());

		for(int i = 0; i < days; i++) {
			for(int j = 0; j < operations.size(); j++) {
				if(operations.get(j)[0] == days -i)
					if(numOfCleanStores[i] >= 1) {
						for(int k = i; k < operations.get(j)[0]; k++) {
							numOfCleanStores[k] -= 1;
						}
						sum+= operations.get(j)[1];
						operations.remove(j);
						numOfCleanStores[i] -= 1;
					}
					else {
						if(operations.get(j)[0] <= days - i) {
							if(numOfCleanStores[i] >= 1) {
								sum+= operations.get(j)[1];
								operations.remove(j);
								numOfCleanStores[i] -= 1;
							}
						}
					}
			}
		}

		System.out.println(sum);

	}
}