#include <iostream>
#include <fstream>
#include <vector>

using namespace std;

const char iname[] = "cuplaj.in";
const char oname[] = "cuplaj.out";
const int  nmax	   = 10200;

ifstream fin(iname);
ofstream fout(oname);

vector<int> Gr[nmax];
int L[nmax], R[nmax], i, k, c, n, m, e, x, y;
int viz[nmax];
int am_cuplat;

int pair_up(int nod)
{	
	if(viz[nod])
		return 0;
	viz[nod] = 1;
	for(vector<int>::iterator it = Gr[nod].begin(); it != Gr[nod].end(); ++it)
	{
		if(pair_up(R[*it]) || R[*it] == 0)
		{
			L[nod] = *it;
			R[*it] = nod;
			return 1;
		}
	}
	return 0;
}

int main()
{
	fin >> n >> m >> e;
	for(i = 1; i <= e; i ++)
	{
		fin >> x >> y;
		Gr[x].push_back(y);
		Gr[y].push_back(x);
	}
	
	am_cuplat = 1;
	while(am_cuplat)
	{	
		for(i = 1; i <= n; i ++)
			viz[i] = 0;
		am_cuplat = 0;
		for(i = 1; i <= n; i ++)
		{

			if(!L[i])
				if(pair_up(i))
				{
					++ c;
					am_cuplat = 1;
				}
		}
	}
	
			
	fout << c << "\n";
	for(i = 1; i <= n; i ++)
		if(L[i])
			fout << i << " " << L[i] << "\n";
	return 0;
}