#include <bits/stdc++.h>

using namespace std;

const int NMAX = 10000;
int capacitate[NMAX + 1][NMAX + 1];
int flux[NMAX + 1][NMAX + 1];
int vis[NMAX + 1], p[NMAX + 1];
vector<int> G[NMAX + 1];
int n_total;

int bfs(int s, int d)
{
    for (int i = 1; i <= n_total; 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;
                p[vecin] = nod;
                q.push(vecin);
            }
        }
    }

    if (!vis[d])
    {
        return 0;
    }

    vector<int> path;
    int x = d;
    while (x != 0 && x != s)
    {
        path.push_back(x);
        x = p[x];
    }
    path.push_back(s);
    reverse(path.begin(), path.end());

    int flow = 1e9;
    for (int i = 0; i < path.size() - 1; i++)
    {
        int a = path[i];
        int b = path[i + 1];
        flow = min(flow, capacitate[a][b] - flux[a][b]);
    }

    for (int i = 0; i < path.size() - 1; i++)
    {
        int a = path[i];
        int b = path[i + 1];
        flux[a][b] += flow;
        flux[b][a] -= flow;
    }

    return flow;
}

void adauga_muchie(int x, int y, int cap)
{
    capacitate[x][y] = cap;
    G[x].push_back(y);
    G[y].push_back(x);
}

int main()
{
    ifstream cin("cuplaj.in");
    ofstream cout("cuplaj.out");

    int N, M, E;
    cin >> N >> M >> E;

    int S = N + M + 1;
    int D = N + M + 2;
    n_total = D;

    for (int i = 1; i <= E; i++)
    {
        int u, v;
        cin >> u >> v;
        adauga_muchie(u, N + v, 1);
    }

    for (int i = 1; i <= N; i++)
    {
        adauga_muchie(S, i, 1);
    }

    for (int i = 1; i <= M; i++)
    {
        adauga_muchie(N + i, D, 1);
    }

    int maxflow = 0;
    while (true)
    {
        int flow = bfs(S, D);
        if (flow == 0)
        {
            break;
        }
        maxflow += flow;
    }

    cout << maxflow << '\n';

    for (int i = 1; i <= N; i++)
    {
        for (auto vecin : G[i])
        {
            if (vecin > N && vecin <= N + M)
            {
                if (flux[i][vecin] == 1)
                {
                    cout << i << " " << (vecin - N) << '\n';
                }
            }
        }
    }

    return 0;
}