#include<iostream>

 #include<string.h>

 using namespace std;

 double a[];

 int main(){

     int n1, n2;

     while(scanf("%d", &n1) != EOF){

         memset(a, , sizeof(a));

         for(int i = ; i <= n1; i++){

             int x;

             double y;

             scanf("%d%lf", &x, &y);

             a[x] += y;

         }

         scanf("%d", &n2);

         for(int i = ; i <= n2; i++){

             int x;

             double y;

             scanf("%d%lf", &x, &y);

             a[x] += y;

         }

         int cnt = ;

         for(int i = ; i <= ; i++){

             if(a[i] != ) cnt++;

         }

         printf("%d", cnt);

         for(int i = ; i >= ; i--){

             if(a[i] != ){

                 printf(" %d %.1lf", i, a[i]);

             }

         }

         printf("\n");

     }

     return ;

 }