#include <bits/stdc++.h>

using namespace std;

const int NMAX = 1e3;
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 muchii[NMAX+1];
int n, m,i, j, e, numar;

int bfs(int s, int d) {
    for(int i = 1; i <= e+2; 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) {
        path.push_back(x);
        x = p[x];
    }
    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;

}

int main() {
	ifstream cin("cuplaj.in");
    ofstream cout("cuplaj.out");
    cin >> n >> m>>e;
    for(int i = 1; i <= e; i++) {
        int x, y;
        int ok=0;
        int ok2=0;
        cin >> x >> y ;
        capacitate[x+1][y+n+1] = 1;
        G[x+1].push_back(y+n+1);
        G[y+n+1].push_back(x+1);
        for(auto vf: G[1])
            if(vf==x+1)
                ok=1;
        for(auto vf: G[y+n+1])
            if(vf==e+2)
                ok2=1;
        if(ok==0)
        {

            G[1].push_back(x+1);
            capacitate[1][x+1]=1;
        }
       if(ok2==0)
        {

            G[y+n+1].push_back(e+2);
            capacitate[y+n+1][e+2]=1;
        }
    }

    int maxflow = 0;
    while(true) {
        int flow = bfs(1, e+2);
        if(flow == 0) {
            break;
        }
        maxflow += flow;
    }
    cout << maxflow<<endl;
 for(i=2;i<=n+1;++i)
 for(j=n+2;j<=n+m+1;++j)
   if(flux[i][j]==1)
   cout<<i-1<<' '<<j-(n+1)<<endl;



}