#include <cmath>
#include <cstdio>
#include <vector>
#include <iostream>
#include <algorithm>
#include <fstream>
#include <queue>
#include <stack>
using namespace std;

const int NMAX = 1000;
const int NEXTRA = 2;
int flux[NMAX + NEXTRA + 1][NMAX + NEXTRA + 1];
int capacitate[NMAX + NEXTRA + 1][NMAX + NEXTRA + 1];
int n;

bool vis[NMAX + NEXTRA + 1];

int p[NMAX + NEXTRA + 1];

vector<int> G[NMAX + NEXTRA + 1];

int bfs(int s, int d) {
    queue<int> q;
    for(int i = 0; i <= n; i++) {
        vis[i] = 0;
        p[i] = 0;
    }

    q.push(s);
    vis[s] = 1;
    while(!q.empty()) {
        int x = q.front();
        q.pop();

        for(auto y : G[x]) {
            if(vis[y] || capacitate[x][y] - flux[x][y] <= 0) continue;

            vis[y] = 1;
            p[y] = x;
            q.push(y);

            if(y == d) break;
        }
    }

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

    vector<int> path;
    int x = d;
    while(x != 0) {
        path.push_back(x);
        x = p[x];
    }
    reverse(path.begin(), path.end());
    int mn = 1e9;
    for(int i = 0; i < path.size() - 1; i++) {
        int x = path[i];
        int y = path[i + 1];
        mn = min(mn, 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] += mn;
        flux[y][x] -= mn;
    }

    return mn;
}

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

    int cL, cR, e;
    cin >> cL >> cR >> e;

    n = cL + cR + 2;

    for(int i = 1; i <= cL; i++) {
        int x = i + 1;
        capacitate[1][x] = 1;
        G[1].push_back(x);
        G[x].push_back(1);
    }

    for(int i = 1; i <= cR; i++) {
        int x = i + cL + 1;
        capacitate[x][n] = 1;
        G[n].push_back(x);
        G[x].push_back(n);
    }

    for(int i = 1; i <= e; i++) {
        int x, y;
        cin >> x >> y;
        x += 1;
        y += 1 + cL;

        capacitate[x][y] = 1;
        G[x].push_back(y);
        G[y].push_back(x);
    }

    int sum = 0;
    while(true) {
        int f = bfs(1, n);
        sum += f;

        if(f == 0) {
            break;
        }
    }

    cout << sum << endl;

    for(int i = 2; i <= cL + 1; i++) {
        for(auto x : G[i]) {
            if(flux[i][x] <= 0) continue;
            cout << i - 1 << " " << x - cL - 1 << endl;
        }
    }

    return 0;
}