#include <bits/stdc++.h>
using namespace std;

const int NMAX = 1e3;
int capacitate[NMAX + 1][NMAX + 1], flux[NMAX + 1][NMAX + 1];
int vis[NMAX + 1], p[NMAX + 1];
vector<int> G[NMAX + 1];
int n, m;

int bfs(int s, int d) {
  for(int i = 1; i <= n; i++) {
    vis[i] = 0;
    p[i] = 0;
  }
  queue<int> q;
  q.push(s);
  vis[s] = 1;
  while(!q.empty()) {
    int nod = q.front();
    q.pop();
    for(auto vecin : G[nod]) {
      if(!vis[vecin] && capacitate[nod][vecin] - flux[nod][vecin] > 0) {
        vis[vecin] = 1;
        q.push(vecin);
        p[vecin] = nod;
      }
    }
  }
  if(vis[d] == 0) {
    return 0;
  }
  vector<int> path;
  while(d != 0) {
    path.push_back(d);
    d = p[d];
  }
  reverse(path.begin(), path.end());
  int flow = 1e9;
  for(int i = 0; i < path.size() - 1; i++) {
    int x = path[i];
    int y = path[i + 1];
    flow = min(flow, capacitate[x][y] - flux[x][y]);
  }
  for(int i = 0; i < path.size() - 1; i++) {
    int x = path[i];
    int y = path[i + 1];
    flux[x][y] += flow;
    flux[y][x] -= flow;
  }
  return flow;
}

int main() {
  ifstream cin("cuplaj.in");
  ofstream cout("cuplaj.out");
  int n_st, m_dr, muchii;
  cin >> n_st >> m_dr >> muchii;
  n = n_st + m_dr + 2;
  int s = 1, d = n;
  for (int i=1; i<=n_st; i++) {
    capacitate[s][i+1] = 1;
    G[s].push_back(i+1);
    G[i+1].push_back(s);
  }
  for (int i=1; i<=m_dr; i++) {
    int nod = n_st + i+ 1;
    capacitate[nod][d] = 1;
    G[nod].push_back(d);
    G[d].push_back(nod);
  }

  for(int i = 1; i <= muchii; i++) {
    int x, y;
    cin >> x >> y;
    int nod_st = x + 1;
    int nod_dr = n_st + y + 1;
    capacitate[nod_st][nod_dr] = 1;
    G[nod_st].push_back(nod_dr);
    G[nod_dr].push_back(nod_st);
  }
  int maxflow = 0;
  while(true) {
    int flow = bfs(1, n);
    if(flow == 0) {
      break;
    }
    maxflow += flow;
  }
  cout << maxflow << endl;
  for (int i = 1; i <= n_st; i++) {
    for (int j = 1; j <= m_dr; j++) {
      if (flux[i + 1][n_st + 1 + j] == 1) {
        cout << i << " " << j << "\n";
      }
    }
  }
}