import java.io.InputStream;
import java.io.IOException;
import java.util.NoSuchElementException;
import java.util.Optional;
import java.util.TreeMap;
import java.util.stream.IntStream;

class Main {
    private static TreeMap<Long, Long> map = new TreeMap<>();
    private static long total;
    public static void main(String... args) {
        FastScanner scanner = new FastScanner();
        int n = scanner.nextInt(), m = scanner.nextInt();
        IntStream.range(0, n).forEach(i -> setMap(scanner.nextLong()));
        IntStream.range(0, m)
            .forEach(i -> setMap(scanner.nextInt(), scanner.nextLong()));
        int counter = n;
        long total = 0;
        while (counter > 0) {
            long lastKey = map.lastKey(),
                num = Math.min(map.get(lastKey), counter);
            total += num * lastKey;
            counter -= num;
            map.remove(lastKey);
        }
        System.out.println(total);
    }
    private static void setMap(long value) {
        map.put(value, Optional.ofNullable(map.get(value)).orElse(0l) + 1);
    }
    private static void setMap(int num, long value) {
        map.put(value, Optional.ofNullable(map.get(value)).orElse(0l) + num);
    }
}
class FastScanner {
    private final InputStream in = System.in;
    private final byte[] buffer = new byte[1024];
    private int ptr = 0;
    private int buflen = 0;
    private boolean hasNextByte() {
        if (ptr < buflen) {
            return true;
        } else {
            ptr = 0;
            try {
                buflen = in.read(buffer);
            } catch (IOException e) {
                e.printStackTrace();
            }
            if (buflen <= 0) {
                return false;
            }
        }
        return true;
    }
    private int readByte() { if (hasNextByte()) return buffer[ptr++]; else return -1; }
    private static boolean isPrintableChar(int c) { return 33 <= c && c <= 126; }
    public boolean hasNext() { while(hasNextByte() && !isPrintableChar(buffer[ptr])) ptr++; return hasNextByte(); }
    public String next() {
        if (!hasNext()) throw new NoSuchElementException();
        StringBuilder sb = new StringBuilder();
        int b = readByte();
        while(isPrintableChar(b)) {
            sb.appendCodePoint(b);
            b = readByte();
        }
        return sb.toString();
    }
    public long nextLong() {
        if (!hasNext()) throw new NoSuchElementException();
        long n = 0;
        boolean minus = false;
        int b = readByte();
        if (b == '-') {
            minus = true;
            b = readByte();
        }
        if (b < '0' || '9' < b) {
            throw new NumberFormatException();
        }
        while(true) {
            if ('0' <= b && b <= '9') {
                n *= 10;
                n += b - '0';
            } else if (b == -1 || !isPrintableChar(b)) {
                return minus ? -n : n;
            } else {
                throw new NumberFormatException();
            }
            b = readByte();
        }
    }
    public int nextInt() {
        long nl = nextLong();
        if (nl < Integer.MIN_VALUE || nl > Integer.MAX_VALUE) throw new NumberFormatException();
        return (int) nl;
    }
    public double nextDouble() { return Double.parseDouble(next()); }
}

Measured memory_bytes: 54324