Kuhn

#include <bits/stdc++.h>
#define maxx 100005
#define inf 2000000000
#define mod 1000000007
#define pii pair<int,int>
#define piii pair<pii,pii>
#define pli pair<long long,int>
#define f first
#define s second
#define in(x) scanf("%d",&x)
#define IN(x) scanf("%lld",&x)
#define inch(x) scanf("%s",x)
#define indo(x) scanf("%lf",&x)
#define pb push_back

typedef long long ll;
typedef unsigned long long ull;

using namespace std;

int n, m, k, a, b, max_matching;
vector<int>g[105], used, R;

int dfs(int node){
    if(used[node]) return 0;
    used[node] = 1;
    for(int i = 0; i < g[node].size(); i++){
        int to = g[node][i];
        if((R[to] == -1) || dfs(R[to])){
            R[to] = node;
            return 1;
        }
    }
    return 0;
}

void Augmented_Path(){
    R.assign(m + 1, -1);
    for(int i = 1; i <= n; i++){
        used.assign(n + 1, 0);
        if(dfs(i))
            max_matching++;
    }
}

int main()
{
  in(n); in(m); in(k);
  while(k --){
    in(a); in(b);
    g[a].pb(b);
  }

  Augmented_Path();
  printf("%d\n",max_matching);
  for(int i = 1; i <= m; i++)
    if(R[i] != -1)
    printf("%d %d\n", R[i], i);
  return 0;
}