#include <bits/stdc++.h>
#define PB push_back
#define EB emplace_back
using namespace std;
const int maxn = 100;
int S, T;
struct edge { int v, f; };
vector<edge> e;
vector<int> g[maxn + 5];
inline void addE(int u, int v, int w) {
	g[u].PB(e.size()), e.PB({v, w});
	g[v].PB(e.size()), e.PB({u, 0});
}
int d[maxn + 5];
int cur[maxn + 5];
bool bfs(int s, int t) {
	memset(d, 127, sizeof(d));
	memset(cur, 0, sizeof(cur));
	queue<int> q;
	d[s] = 0;
	q.push(s);
	while (!q.empty()) {
		int u = q.front(); q.pop();
		for (int eid : g[u]) {
			int v = e[eid].v, f = e[eid].f;
			if (d[v] > T && f) {
				d[v] = d[u] + 1;
				if (v == t) return 1;
				q.push(v);
			}
		}
	}
	return 0;
}
int dfs(int u, int t, int fl) {
	if (u == t) return fl;
	int rs = 0;
	for (int i = cur[u]; i < g[u].size(); i++) {
		cur[u] = i;
		int eid = g[u][i];
		int v = e[eid].v, f = e[eid].f;
		if (d[v] == d[u] + 1 && f) {
			int nf = dfs(v, t, min(fl, f));
			fl -= nf, rs += nf;
			e[eid].f -= nf, e[eid ^ 1].f += nf;
		}
		if (!fl) break;
	}
	return rs;
}
int dinic(int s, int t) {
	int rs = 0;
	while (bfs(s, t)) rs += dfs(s, t, INT_MAX);
	return rs;
}
int main() {
	int l, r, m;
	scanf("%d%d%d", &l, &r, &m);
	S = l + r + 1, T = S + 1;
	for (int i = 1; i <= l; i++) addE(S, i, 1);
	for (int i = 1; i <= r; i++) addE(l + i, T, 1);
	for (int i = 1; i <= m; i++) {
		int u, v;
		scanf("%d%d", &u, &v);
		addE(u + 1, v + l + 1, 1);
	}
	printf("%d\n", dinic(S, T));
	for (int i = 1; i <= l; i++)
		for (int eid : g[i]) {
			int v = e[eid].v, f = e[eid].f;
			if (v != S && !f) printf("%d %d\n", i - 1, v - l - 1);
		}
}