#include <bits/stdc++.h>
#define Nmax 10005
#define pb push_back
#define mp make_pair
using namespace std;

ifstream fin("cuplaj.in");
ofstream fout("cuplaj.out");

int N, M, E;
vector<pair<int, int> > G[Nmax];
vector<int> edge;
int f[Nmax], x[Nmax], y[Nmax], ans;
bool vis[Nmax], in[Nmax], ok;
bool pos[4] = {0, 1, 1, 0};

void DFS(int node, int nr, int st) {
    for (auto it: G[node])
      if (!vis[it.first] && f[it.second] == (nr + 1) % 2) if (!ok && in[it.first] == pos[nr]) {
            edge.pb(it.second);
            vis[it.first] = 1;
            if (nr < 3) {
                  DFS(it.first, nr + 1, st);
                  edge.pop_back();
                  vis[it.first] = 0;
            }
      }

    if (nr == 3) {
        f[edge[0]] = f[edge[2]] = 1;
        f[edge[1]] = 0;
        ans++;
        ok = 1;
        return;
    }
}
int main()
{
    fin >> N >> M >> E;
    for (int i = 1; i <= E; ++i) {
        fin >> x[i] >> y[i]; y[i] += N;
        G[x[i]].pb(mp(y[i], i));
        G[y[i]].pb(mp(x[i], i));
    }

    for (int i = 1; i <= N; ++i)
    for (auto it: G[i])
       if (!in[it.first])  {
           in[i] = in[it.first] = 1;
           f[it.second] = 1;
           ++ans;
           break;
        }

    for (int i = 1; i <= N; ++i)
        if (!in[i]) ok = 0, edge.clear(), memset(vis, 0, sizeof(vis)), DFS(i, 1, i);
    fout <<  ans << '\n';
    for (int i = 1; i <= E; ++i)
        if (f[i]) fout << x[i] << " " << y[i] - N << '\n';
    return 0;
}