#include<bits/stdc++.h>
using namespace std;
template <typename T> inline void read(T &x)
{
	x=0;short f=1;char c=getchar();
	for(;c<'0'||c>'9';c=getchar()) if(c=='-') f=-1;
	for(;c>='0'&&c<='9';c=getchar()) x=(x<<1)+(x<<3)+(c^48);
	x*=f;return;
}
#define int long long
const int N=105,M=5005,inf=1e18;
#define pa(x) (x%2==0?x-1:x+1)
int L,R,m,S,T;
struct edge{
	int v,nxt,c;
}e[M*2];
int head[N],cur[N],cnt=1;
void add(int u,int v,int c)
{
	e[cnt].v=v,e[cnt].c=c,e[cnt].nxt=head[u],head[u]=cnt++;
	e[cnt].v=u,e[cnt].c=0,e[cnt].nxt=head[v],head[v]=cnt++;
}
queue<int>q;
int dis[N];
bool bfs()
{
	memset(dis,-1,sizeof dis);
	while(!q.empty()) q.pop();
	dis[S]=0,q.push(S);
	while(!q.empty())
	{
		int u=q.front();q.pop();
		cur[u]=head[u];
		for(int i=head[u];i;i=e[i].nxt)
		{
			int v=e[i].v,c=e[i].c;
			if(dis[v]==-1&&c)
			{
				dis[v]=dis[u]+1;
				if(v==T) return true;
				q.push(v);
			}
		}
	}
	return false;
}
int find(int u,int limit)
{
	if(u==T) return limit;
	int flow=0;
	for(int i=cur[u];i;i=e[i].nxt)
	{
		cur[u]=i;
		int v=e[i].v,c=e[i].c;
		if(dis[v]==dis[u]+1&&c)
		{
			int t=find(v,min(c,limit-flow));
			if(!t) dis[v]=-1;
			e[i].c-=t,e[pa(i)].c+=t,flow+=t;
		}
	}
	return flow;
}
int dinic()
{
	int r=0,flow;
	while(bfs()) while(flow=find(S,inf)) r+=flow;
	return r;
}
array<int,3>E[N];
signed main()
{
	read(L),read(R),read(m);
	S=0,T=L+R+1;
	for(int i=1;i<=L;++i)
		add(S,i,1);
	for(int i=1;i<=R;++i)
		add(i+L,T,1);
	for(int i=1;i<=m;++i)
	{
		int u,v,c;read(u),read(v);
		E[i][0]=u,E[i][1]=v;
		++u,++v; 
		add(u,v+L,1);
		E[i][2]=cnt-2;
	}
	printf("%lld\n",dinic());
	for(int i=1;i<=m;++i)
		if(e[E[i][2]].c==0)
			printf("%d %d\n",E[i][0],E[i][1]);
}