#include <bits/stdc++.h>
#define pb push_back
using namespace std;
ifstream fi("cuplaj.in");
ofstream fo("cuplaj.out");

const int NMAX = 10005;
const int EMAX = 100005;

short F[EMAX];
bool C[EMAX];
vector < pair<short, int> > G[NMAX];
int n, m, e;
queue <short> Q;
bool viz[NMAX];
short p[NMAX];
vector < pair<short, short> > muchiiRez;
int k;
int ce[NMAX * 3];
int opus[EMAX];

int bfs()
{
    memset(viz, 0, sizeof(viz));
    memset(p, 0, sizeof(p));
    memset(ce, 0, sizeof(ce));

    while (!Q.empty())
        Q.pop();

    Q.push(1);
    viz[1] = 1;

    while (!Q.empty())
    {
        int curr = Q.front();
        Q.pop();

        for (auto v: G[curr])
        {
            int nod = v.first;
            int nrm = v.second;

            if (F[nrm] != C[nrm] && !viz[nod])
            {
                p[nod] = curr;
                ce[nod] = nrm; /// cu asta mergem inapoi

                Q.push(nod);
                viz[nod] = 1;
                if (nod == n + m + 2)
                    return 1;
            }
        }
    }
    return viz[n + m + 2];
}

int main()
{
    fi >> n >> m >> e;

    for (int i = 1; i <= e; i++)
    {
        int u, v;
        fi >> u >> v;
        v += n;
        u++;
        v++;
        G[u].pb({v, ++k});
        C[k] = 1;
        G[v].pb({u, ++k});
        opus[k] = k - 1;
        opus[k - 1] = k;
    }

    for (int i = 2; i <= n + 1; i++)
    {
        G[1].pb({i, ++k});
        C[k] = 1;
        G[i].pb({1, ++k});
        opus[k] = k - 1;
        opus[k - 1] = k;
    }

    for (int i = n + 2; i <= n + m + 1; i++)
    {
        G[i].pb({n + m + 2, ++k});
        C[k] = 1;
        G[n + m + 2].pb({i, ++k});
        opus[k] = k - 1;
        opus[k - 1] = k;
    }

    int rez = 0;

    while (bfs())
    {
        int minim = 100;

        for (int i = n + m + 2; i != 1; i = p[i])
        {
            minim = min(minim, C[ce[i]] - F[ce[i]]);
        }

        for (int i = n + m + 2; i != 1; i = p[i])
        {
            F[ce[i]] += minim;
            F[opus[ce[i]]] -= minim;
        }

        rez += minim;
    }

    fo << rez << "\n";

    for (int i = 2; i <= n + 1; i++)
    {
        for (auto v: G[i])
        {
            if (C[v.second] == F[v.second] && C[v.second] == 1)
                fo << i - 1 << " " << v.first - (n + 1) << "\n";
        }
    }

    return 0;
}