#include <bits/stdc++.h>

using namespace std;

#define ll long long
#define ull unsigned ll
#define vec vector
#define flist forward_list
#define um unordered_map
#define us unordered_set
#define prioq priority_queue
#define all(x) x.begin(), x.end()
#define pb push_back
#define pf push_front
#define fi first
#define se second
#define mp make_pair
#define mt make_tuple
#define ld long double
#define pll pair<ll, ll>

#define LL_MAX LLONG_MAX
#define LL_MIN LLONG_MIN
#define ULL_MAX ULLONG_MAX
#define ULL_MIN 0
#define LD_MAX LDBL_MAX
#define LD_MIN LDBL_MIN

#define nl '\n'

#define vv(type, name, n, ...) vector<vector<type>> name(n, vector<type>(__VA_ARGS__))
#define vvv(type, name, n, m, ...)                                                                                     \
    vector<vector<vector<type>>> name(n, vector<vector<type>>(m, vector<type>(__VA_ARGS__)))

// https://trap.jp/post/1224/
#define rep1(n) for(ll i=0; i<(ll)(n); ++i)
#define rep2(i,n) for(ll i=0; i<(ll)(n); ++i)
#define rep3(i,a,b) for(ll i=(ll)(a); i<(ll)(b); ++i)
#define rep4(i,a,b,c) for(ll i=(ll)(a); i<(ll)(b); i+=(c))
#define cut4(a,b,c,d,e,...) e
#define rep(...) cut4(__VA_ARGS__,rep4,rep3,rep2,rep1)(__VA_ARGS__)
#define rep1e(n) for(ll i=1; i<=(ll)(n); ++i)
#define rep2e(i,n) for(ll i=1; i<=(ll)(n); ++i)
#define rep3e(i,a,b) for(ll i=(ll)(a); i<=(ll)(b); ++i)
#define rep4e(i,a,b,c) for(ll i=(ll)(a); i<=(ll)(b); i+=(c))
#define repe(...) cut4(__VA_ARGS__,rep4e,rep3e,rep2e,rep1e)(__VA_ARGS__)
#define per1(n) for(ll i=((ll)n)-1; i>=0; --i)
#define per2(i,n) for(ll i=((ll)n)-1; i>=0; --i)
#define per3(i,a,b) for(ll i=((ll)a)-1; i>=(ll)(b); --i)
#define per4(i,a,b,c) for(ll i=((ll)a)-1; i>=(ll)(b); i-=(c))
#define per(...) cut4(__VA_ARGS__,per4,per3,per2,per1)(__VA_ARGS__)
#define per1e(n) for(ll i=((ll)n); i>=1; --i)
#define per2e(i,n) for(ll i=((ll)n); i>=1; --i)
#define per3e(i,a,b) for(ll i=((ll)a); i>=(ll)(b); --i)
#define per4e(i,a,b,c) for(ll i=((ll)a); i>=(ll)(b); i-=(c))
#define pere(...) cut4(__VA_ARGS__,per4e,per3e,per2e,per1e)(__VA_ARGS__)
#define rep_subset(i,s) for(ll i=(s); i>=0; i=(i==0?-1:(i-1)&(s)))
// #define forit(v) for (auto it = v.begin(); it != v.end(); it++)
// #define forit2(it, v) for (auto it = v.begin(); it != v.end(); it++)
// #define forrit(v) for (auto it = v.rbegin(); it != v.rend(); it++)
// #define forrit2(it, v) for (auto it = v.rbegin(); it != v.rend(); it++)

// #ifdef i_am_noob
#define bug(...) cerr << "#" << __LINE__ << ' ' << #__VA_ARGS__ << "- ", _do(__VA_ARGS__)
template<typename T> void _do(vector<vector<T>> x){cerr << "\n"; for(auto i: x) {for(auto j : i) {cerr << j << ' ';} cerr << "\n";}}
template<typename T> void _do(vector<T> x){for(auto i: x) cerr << i << ' ';cerr << "\n";}
template<typename T> void _do(set<T> x){for(auto i: x) cerr << i << ' ';cerr << "\n";}
template<typename T> void _do(unordered_set<T> x){for(auto i: x) cerr << i << ' ';cerr << "\n";}
template<typename T> void _do(T && x) {cerr << x << endl;}
template<typename T, typename ...S> void _do(T && x, S&&...y) {cerr << x << ", "; _do(y...);}
// #else
// #define bug(...) 777771449
// #endif

const ll MOD = 1e9 + 7;

const string FILENAME = "cuplaj";
ifstream fin(FILENAME + ".in");
ofstream fout(FILENAME + ".out");

#define cin fin
#define cout fout

struct edge
{
	ll begin, end, res, inv;
};

int main()
{
	ll n, m, e;
	
	cin >> n >> m >> e;
	
	vec<flist<ll>> adj(n + m + 2);
	vec<edge> edges(e + n + m);
	
	rep(e)
	{
		ll a, b;
		
		cin >> a >> b;
		
		b += n;
		
		edges[i].begin = a;
		edges[i].end = b;
		edges[i].res = 1;
		edges[i].inv = 0;
		
 		adj[a].pf(i);
		adj[b].pf(i);
	}
	
	rep(n)
	{
		edges[e + i].begin = 0;
		edges[e + i].end = i + 1;
		edges[e + i].res = 1;
		edges[e + i].inv = 0;
		
		adj[0].pf(e + i);
		adj[i + 1].pf(e + i);
	}
	
	rep(m)
	{
		edges[e + n + i].begin = n + i + 1;
		edges[e + n + i].end = n + m + 1;
		edges[e + n + i].res = 1;
		edges[e + n + i].inv = 0;
		
		adj[n + m + 1].pf(e + n + i);
		adj[n + i + 1].pf(e + n + i);
	}
	
	ll maxFlow = 0;
	vec<bool> vis(n + m + 2);
	vec<ll> parent(n + m + 2);
	
	while(true)
	{
		bool foundPath = 0;
		
		rep(n + m + 2) vis[i] = parent[i] = 0;
		queue<ll> nn;
		ll node;
		
		vis[0] = 1;
		nn.push(0);
		
		while(!nn.empty())
		{
			node = nn.front();
			nn.pop();
			
			if(node == n + m + 1)
			{
				foundPath = 1;
				break;
			}
			
			for(auto ei : adj[node])
			{
				// bug(node, ei);
				edge& enei = edges[ei];
				
				if(enei.begin == node)
				{
					if(!vis[enei.end] && enei.res > 0)
					{
						vis[enei.end] = 1;
						parent[enei.end] = ei;
						nn.push(enei.end);
					}
				}
				else
				{
					if(!vis[enei.begin] && enei.inv > 0)
					{
						vis[enei.begin] = 1;
						parent[enei.begin] = ei;
						nn.push(enei.begin);
					}
				}
			}
		}
		
		if(!foundPath) break;
		
		maxFlow++;
		
		while(node != 0)
		{
			edge& enei = edges[parent[node]];
			
			if(enei.end == node)
			{
				enei.res--;
				enei.inv++;
				node = enei.begin;
			}
			else
			{
				enei.inv--;
				enei.res++;
				node = enei.end;
			}
		}
	}
	
	cout << maxFlow << nl;
	
	rep(e)
	{
		if(edges[i].res == 0)
		{
			if(edges[i].begin > n)
				cout << edges[i].begin - n << ' ';
			else
				cout << edges[i].begin << ' ';
			
			if(edges[i].end > n)
				cout << edges[i].end - n << nl;
			else
				cout << edges[i].end << nl;
		}
	}
	
    return 0;
}