//Crimson flames tied through my ears
//Rollin' high and mighty traps
//Pounced with fire on flaming roads
//Using ideas as my maps
//"We'll meet on edges, soon," said I
//Proud 'neath heated brow
//Ah, but I was so much older then
//I'm younger than that now.
//
//Half-cracked prejudice leaped forth
//"Rip down all hate," I screamed
//Lies that life is black and white
//Spoke from my skull, I dreamed
//Romantic facts of musketeers
//Foundationed deep, somehow
//Ah, but I was so much older then
//I'm younger than that now.
//
//Girls' faces formed the forward path
//From phony jealousy
//To memorizing politics
//Of ancient history
//Flung down by corpse evangelists
//Unthought of, thought, somehow
//Ah, but I was so much older then
//I'm younger than that now.
//A self-ordained professor's tongue
//Too serious to fool
//Spouted out that liberty
//Is just equality in school
//"Equality," I spoke the word
//As if a wedding vow
//Ah, but I was so much older then
//I'm younger than that now.
//
//In a soldier's stance, I aimed my hand
//At the mongrel dogs who teach
//Fearing not that I'd become my enemy
//In the instant that I preach
//My existence led by confusion boats
//Mutiny from stern to bow
//Ah, but I was so much older then
//I'm younger than that now.
//
//Yes, my guard stood hard when abstract threats
//Too noble to neglect
//Deceived me into thinking
//I had something to protect
//Good and bad, I define these terms
//Quite clear, no doubt, somehow
//Ah, but I was so much older then
//I'm younger than that now.

#pragma GCC optimize("O3,unroll-loops")
#include<bits/stdc++.h>
using namespace std;
#include<ext/pb_ds/assoc_container.hpp>
#include<ext/pb_ds/hash_policy.hpp>
using namespace __gnu_pbds;
/*=====================================================================*/
#define ll long long
//#define int ll
#define pii pair<int,int>
#define vi vector<int>
#define vii vector<pii>
#define pdd pair<double,double>
#define ull unsigned long long
#define pb push_back
#define rep(i,n) for(int i=0;i<(int)(n);++i)
#define all(s) (s).begin(),(s).end()
#define repd(i,n) for(int i=(int)(n)-1;i>=0;--i)
#define forr(i,a,b,c) for(int i=(int)(a);i<=(int)(b);i+=(int)(c))
#define forn(i,p,n) for(int i=(int)(p);i<=(int)(n);++i)
#define ford(i,p,n) for(int i=(int)(n);i>=(int)(p);--i)
#define foreach(i,c) for(__typeof(c.begin())i=(c.begin());i!=(c).end();++i)
#define INF 0x3f3f3f3f
#define PI acos(-1)
#define modcg(x) if(x>=mod)x-=mod;
#define modcl(x) if(x<0)x+=mod;
#define lowbit(x) ((x)&(-(x)))
#define ckmax(x,y) x=max(x,y)
#define ckmin(x,y) x=min(x,y)
/*=====================================================================*/
mt19937 GeN(chrono::system_clock::now().time_since_epoch().count());
int Rand(int l,int r)
{
	uniform_int_distribution<>RAND1(l,r);
	return RAND1(GeN);
}
struct Fastmod
{
	int mod,b;
	typedef __int128 lll;
	void init(int m)
	{
		mod=m;
		b=((lll)1<<64)/mod;
	}
	int operator()(ull a)
	{
		int q=((lll)a*b)>>64,r=a-q*mod;
		modcg(r);
		return r;
	}
}MOD;
int mul(int a,int b)
{
	return MOD(a*b);
}
char *p1,*p2,buf[100000];
#define nc() (p1==p2 && (p2=(p1=buf)+fread(buf,1,100000,stdin),p1==p2)?EOF:*p1++)
int read()
{
    int x=0,f=1;
    char ch=nc();
    while(ch<48||ch>57)
    {
        if(ch=='-')
            f=-1;
        ch=nc();
    }
    while(ch>=48&&ch<=57)
        x=x*10+ch-48,ch=nc();
   	return x*f;
}
void write(int x)
{
    if(x<0)
        putchar('-'),x=-x;
    if(x>9)
        write(x/10);
    putchar(x%10+'0');
    return;
}
/*======================================================================*/
//think twice,code once
//think once,debug forever
const int MAXN=2e6+10;
int n,m;
clock_t stime;
double ntime()
{
	return (double)(clock()-stime)/CLOCKS_PER_SEC;
}
mt19937 gen;
namespace Flow
{
	const int MAXN=4e6+10,MAXM=1.2e7+10;
	struct edge
	{
		int to,c,id;
	}e[MAXM];
	int head;
	int s,t;
	vi v[MAXN];
	void add(int x,int y,int c)
	{
		e[head]={y,c};
		v[x].pb(head++);
	}
	vi E;
	void add_edge(int x,int y,int c,int t)
	{
		if(t)
		{
			E.pb(head);
		}
		add(x,y,c);add(y,x,0);
	}
	int dist[MAXN];
	bool bfs()
	{
		forn(i,1,t)
		{
			dist[i]=INF; 
		}
		dist[s]=0;
		queue<int> q;
		q.push(s);
		while(!q.empty())
		{
			int now=q.front();q.pop();
			for(int i:v[now])
			{
				int u=e[i].to,c=e[i].c;
				if(dist[u]==INF&&c)
				{
					dist[u]=dist[now]+1;
					q.push(u);
				}
			}
		}
		return dist[t]!=INF;
	}
	int cur[MAXN];
	int ans=0;
	int dfs(int now,int flow)
	{
		if(now==t)
		{
			return flow;
		}
		int all=flow;
		for(int &I=cur[now];I<v[now].size();I++)
		{
			int i=v[now][I];
			int u=e[i].to,c=e[i].c;
			if(dist[u]==dist[now]+1&&c)
			{
				int del=dfs(u,min(c,all));
				e[i].c-=del;e[i^1].c+=del;
				all-=del;
				if(!all)
				{
					break;
				}
			}
		}
		return flow-all;
	}
	void dinic()
	{
		ans=0;
		while(bfs()&&ntime()<1.7)
		{
			forn(i,1,t)
			{
				cur[i]=0;
			}
			ans+=dfs(s,INF);
		}
		write(ans);puts("");
		int cnt=0;
		for(int i:E)
		{
			cnt++;
			if(!e[i].c)
			{
				write(cnt);puts("");
			}
		}
	}
};
using Flow::s;
using Flow::t;
using Flow::add_edge; 
void solve()
{
	clock_t T=clock();
	int n1,n2,m;
//	cin>>n1>>n2>>m;
	n1=read(),n2=read(),m=read(); 
	s=n1+n2+1;t=s+1;
	forn(i,1,n1)
	{
		add_edge(s,i,1,0);
	}
	forn(i,1,n2)
	{
		add_edge(i+n1,t,1,0);
	}
	forn(i,1,m)
	{
		int x,y;
//		cin>>x>>y;
		x=read();y=read();
		add_edge(x,y+n1,1,1);
	}
	stime=clock();
	Flow::dinic();
}
/*======================================================================*/
signed main()
{
    cin.tie(0);
    cout.tie(0);
	std::ios::sync_with_stdio(false);
//#define Hank2007
#ifdef Hank2007
	freopen("input.txt","r",stdin);
	freopen("output1.txt","w",stdout);
#endif
  	/*====================================================================*/
  	int TEST_CASE=1;
//	cin>>TEST_CASE;
  	while(TEST_CASE--)
  	{
  		solve();
  	}
  	return 0;
}
/*
//
start coding at
finish debugging at
*/