import java.io.*;
import java.util.*;

public class Main {
    public static void main(String[] args) {
        FastScanner sc = new FastScanner();
        int n = sc.nextInt();
        int m = sc.nextInt();
        long [] a = new long[n];
        int[][] b = new int[m][2];

        for(int i=0; i<n; i++){
            a[i] = sc.nextLong();
        }
        for(int i=0; i<m; i++){
            b[i][0] = sc.nextInt();
            b[i][1] = sc.nextInt();
        }

        Arrays.sort(b, (mb1, mb2)-> mb2[1] - mb1[1]);

        long[] add = new long[n];
        int count = 0;
        int mcount = 0;
        int bcount = 0;
        while(count < n){
            if(mcount == b[bcount][0]){
                bcount++;
                mcount = 0;
            }
            if(bcount == m) break;
            add[count] = b[bcount][1];
            mcount++;
            count++;
        }

        Arrays.sort(a);

        for(int i=0; i<n; i++){
            if(i >= count) break;
            if(a[i] < add[i]){
                a[i] = add[i];
            }else{
                break;
            }
        }

        long ans = 0;
        for(long ma: a){
            ans += ma;
        }

        System.out.println(ans);
    }

    private static 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: 39424