import java.io.*;

class Main {
    public static void main(String[] args) throws IOException {
        InputStreamReader isr = new InputStreamReader(System.in);
        BufferedReader in = new BufferedReader(isr);
        OutputStreamWriter osw = new OutputStreamWriter(System.out);
        BufferedWriter out = new BufferedWriter(osw);

        int cnt = 0;
        double[] as = new double[1010];

        String[] strs = in.readLine().split(" ");
        int k1 = Integer.parseInt(strs[0]);
        for (int i = 0; i < k1; i++) {
            int n = Integer.parseInt(strs[2 * i + 1]);
            double a = Double.parseDouble(strs[2 * i + 2]);
            if (as[n] == 0) {
                cnt++;
            }
            as[n] += a;
        }

        strs = in.readLine().split(" ");
        int k2 = Integer.parseInt(strs[0]);
        for (int i = 0; i < k2; i++) {
            int n = Integer.parseInt(strs[2 * i + 1]);
            double a = Double.parseDouble(strs[2 * i + 2]);
            if (as[n] == 0) {
                cnt++;
            }
            as[n] += a;
        }

        out.write(cnt + "");
        for (int i = 1001; i >= 0; i--) {
            if (as[i] != 0) {
                out.write(String.format(" %d %.1f", i, as[i]));
            }
        }

        in.close();
        isr.close();
        out.flush();
        out.close();
        osw.close();
    }
}