import java.io.OutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.PrintWriter;
import java.util.Arrays;
import java.util.stream.LongStream;
import java.io.IOException;
import java.util.Objects;
import java.io.Closeable;
import java.util.Comparator;
import java.util.NoSuchElementException;
import java.io.InputStream;

/**
 * Built using CHelper plug-in
 * Actual solution is at the top
 *
 * @author HBonsai
 */
public class Main {
    public static void main(String[] args) {
        InputStream inputStream = System.in;
        OutputStream outputStream = System.out;
        FastScanner in = new FastScanner(inputStream);
        PrintWriter out = new PrintWriter(outputStream);
        DIntegerCards solver = new DIntegerCards();
        solver.solve(1, in, out);
        out.close();
    }

    static class DIntegerCards {
        public void solve(int testNumber, FastScanner in, PrintWriter out) {
            int N = in.nextInt();
            int M = in.nextInt();
            long[] A = in.nextLongArray(N);
            Arrays.sort(A);
            int[] B = new int[M];
            long[] C = new long[M];
            Pair[] pairs = new Pair[M];
            for (int i = 0; i < M; i++) {
                B[i] = in.nextInt();
                C[i] = in.nextLong();
                pairs[i] = new Pair(B[i], C[i]);
            }
            Arrays.sort(pairs, Comparator.comparingLong(Pair::getSecond).reversed());
            int i = 0;
            int i_p = 0;
            out:
            while (i < N && i_p < M) {
                Pair card = pairs[i_p];
                int remain = card.first;
                long value = card.second;
                while (remain > 0) {
                    if (i >= N) break out;
                    if (A[i] < value) {
                        A[i] = value;
                        remain--;
                    }
                    i++;
                }
                i_p++;
            }
            long ans = Arrays.stream(A).sum();
            out.println(ans);
        }

        class Pair {
            public int first;
            public long second;

            public Pair(int first, long second) {
                this.first = first;
                this.second = second;
            }

            public long getSecond() {
                return second;
            }

            public boolean equals(Object o) {
                if (this == o) return true;
                if (o == null || getClass() != o.getClass()) return false;
                Pair pair = (Pair) o;
                return first == pair.first &&
                        second == pair.second;
            }

            public int hashCode() {
                return Objects.hash(first, second);
            }

        }

    }

    static class FastScanner implements Closeable {
        private final InputStream in;
        private final byte[] buffer = new byte[1024];
        private int ptr = 0;
        private int buflen = 0;

        public FastScanner(InputStream in) {
            this.in = in;
        }

        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 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 long[] nextLongArray(int n) {
            long[] res = new long[n];
            for (int i = 0; i < n; i++) {
                res[i] = nextLong();
            }
            return res;
        }

        public void close() {
            try {
                in.close();
            } catch (IOException e) {
                e.printStackTrace();
            }
        }

    }
}



Measured memory_bytes: 34484