#include <iostream>
#include <fstream>
#include <vector>
#include <algorithm>
#include <queue>
#include <functional>
#include <utility>
#include <climits>
using namespace std;

const int NMAX = 1e3;
int capacitate[NMAX +1][NMAX + 1], flux[NMAX + 1][NMAX + 1];
int vis[NMAX +1], p[NMAX + 1];
vector<int> G[NMAX +1];
int n,m;

int bfs(int s, int d){
    for(int i=0; i<=n+m+1; 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;
                q.push(vecin);
                p[vecin]=nod;
            }
        }
    }
    if(vis[d]==0){
        return 0;
    }
    vector<int> path;
    while(d!=0){
        path.push_back(d);
        d=p[d];
    }
    reverse(path.begin(), path.end());
    int flow = 1e9;
    for(int i=0; i < path.size() - 1; i++){
        int x=path[i];
        int y=path[i+1];
        flow = min(flow, 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]+=flow;
        flux[y][x]-=flow;
    }

    return flow;

}


int main(){

    ifstream cin("cuplaj.in");
    ofstream cout("cuplaj.out");
    cin>>n>>m;
    int l;
    cin>>l;
    
    int d=n+m+1;
    
    for(int i=1; i<=n; i++){
        capacitate[0][i]=1;
        G[0].push_back(i);
        G[i].push_back(0);
    }

    for(int i=n+1; i<=n+m; i++){
        capacitate[i][d]=1;
        G[i].push_back(d);
        G[d].push_back(i);
    }

    for(int i=1; i<=l; i++){
        int x,y;
        cin>>x>>y;
        y+=n;
        capacitate[x][y] = 1;

        if(find(G[x].begin(), G[x].end(), y) == G[x].end()){
            G[x].push_back(y);
            G[y].push_back(x);
        }
    }
    int maxflow=0;
    while(true){
        int flow = bfs(0,d);
        if(flow == 0){
            break;
        }
        maxflow+=flow;
    }

    cout<<maxflow<<'\n';

    for(int i=1; i<=n; i++){
        for(int j=n+1; j<=n+m; j++){
            if(flux[i][j] > 0){
                cout<<i<<" "<<(j-n)<<'\n';
            }
        }
    }
    
    return 0;
}