PAT1002

#include<iostream>
#include<string>
#include<sstream>
#include<map>
#include<vector>
using namespace std;

int main()
{
    string s1, s2;
    while(getline(cin, s1) && getline(cin, s2))
    {
        stringstream ss1, ss2;
        map<int, float> m;
        vector<pair<int, float> > vec;
        ss1.str(s1);
        ss2.str(s2);
        float i,j;
        ss1>>i;
        ss2>>i;
        float n1[11] = {0}, n2[11] = {0};
        while(ss1>>i>>j)
        {
           m[(int)i] += j;
        }
        while(ss2>>i>>j)
        {
            m[(int)i] += j;
        }
        for(map<int, float>::reverse_iterator it = m.rbegin(); it != m.rend(); it++)
        {
            if((*it).second != 0)
                vec.push_back(*it);
        }
        cout<<vec.size();
        for(int i = 0; i < vec.size(); i++)
            printf(" %d %.1f", vec[i].first, vec[i].second);
    }
}