#include<fstream>
#include<vector>
#include<queue>
using namespace std;
ifstream fin("cuplaj.in");
ofstream fout("cuplaj.out");
vector <int> v[40003];
queue <int> q;
int n, f[20003][20003], c[20003][20003], viz[50003], s, d, flow, fmini, j;
int t[50003], e, st, dr;

int bfs(){
    int i, j, nod, fiu;
    while (!q.empty()) //golim coada
        q.pop();
    q.push(s);
    for (i = 1; i <= n; i++)
        viz[i] = 0;
    viz[s] = 1;
    while (!q.empty()){
        nod = q.front(); q.pop();
        for (j = 0; j < v[nod].size(); j++){
            fiu = v[nod][j];
            if (c[nod][fiu] != f[nod][fiu] and viz[fiu] == 0){
                viz[fiu] = 1;
                q.push(fiu);
                t[fiu] = nod;
                if (fiu == d) return 1; //daca se poate ajunge la sfarsit inseamna ca exista cale mai buna
            }
        }
    }
    return 0;
}

void flux(){
    int nod;
    flow = 0;
    while (bfs()){
        for (j = 0; j < v[d].size(); j++)
            if (viz[v[d][j]] == 1 and c[v[d][j]][d] != f[v[d][j]][d]){
                t[d] = v[d][j];
                /*fmini = 9999999;
                nod = d;
                while (nod != s){
                    fmini = min(fmini, c[t[nod]][nod] - f[t[nod]][nod]);
                    nod = t[nod];
                }*/
                fmini = 1;
                nod = d;
                while (nod != s){
                    f[t[nod]][nod] += fmini;
                    f[nod][t[nod]] -= fmini;
                    nod = t[nod];
                }
                flow += fmini;
            }
    }
    fout << flow << '\n';
}

void citire(){ // e buna
    int i, a, b;
    fin >> st >> dr >> e;
    n = st + dr + 2;
    for (i = 1; i <= e; i++){
        fin >> a >> b;
        v[a].push_back(b + st);
        v[b + st].push_back(a);
        c[a][b + st] = 1;
    }
     //construim reteaua de transport
    s = n - 1; d = n;
    for (i = 1; i <= st; i++){ // s -> fiecare nod din st
        v[s].push_back(i);
        v[i].push_back(s);
        c[s][i] = 1;
    }
    for (i = 1; i <= dr; i++){ // fiecare nod din dr -> d
        v[i + st].push_back(d);
        v[d].push_back(i + st);
        c[i + st][d] = 1;
    }
}

int main(){
    citire();
    flux();
    for (int i = 1; i <= n; i++){
        for (int j = 1; j <= n; j++){
            if (f[i][j] == 1 and i != s and j != d)
                fout << i << " " << j - st << '\n';
        }
    }
}