#include <iostream>
#include <cstdio>
#include <cstring>
using namespace std;
int main()
{
double a[1002];
memset(a,0,sizeof(a));
int s1,s2;
cin>>s1;
int e;
double c;
while(s1--){
cin>>e>>c;
a[e]+=c;
}
cin>>s2;
while(s2--){
cin>>e>>c;
a[e]+=c;
}
int num=0;
for(int i=0;i<11;i++){
if(a[i]!=0){
num++;
}
}
printf("%d",num);
for(int i=1001;i>=0;i--){
if(a[i]!=0){
printf(" ");
printf("%d %.1lf",i,a[i]);
}
}
return 0;
}