#include <bits/stdc++.h>
using namespace std;
const int INF = 0x3f3f3f3f;
const int mod = 1e9 + 7;
const int N = 4010;
int head[N], cnt = 1, dis[N], s, t, cur[N], in[N];
struct edge {
  int next, to, w;
} e[N << 5];
void add(int u, int v, int w) {
  e[++cnt].next = head[u];
  e[cnt].to = v;
  e[cnt].w = w;
  head[u] = cnt;
}
void add_edge(int u, int v, int w) {
  add(u, v, w);
  add(v, u, 0);
}
bool bfs(int s) {
  for (int i = 1; i <= t; i++) dis[i] = -1;
  dis[s] = 0;
  queue<int> q;
  q.push(s);
  while (!q.empty()) {
    int u = q.front();
    q.pop();
    for (int i = head[u]; i; i = e[i].next) {
      int v = e[i].to;
      if (e[i].w && dis[v] == -1) {
        dis[v] = dis[u] + 1;
        q.push(v);
      }
    }
  }
  return dis[t] != -1;
}
int dfs(int u, int flo) {
  if (u == t) return flo;
  int detla = flo;
  for (int i = cur[u]; i; i = e[i].next) {
    cur[u] = e[i].next;
    int v = e[i].to;
    if (e[i].w && dis[v] == dis[u] + 1) {
      int d = dfs(v, min(detla, e[i].w));
      e[i].w -= d;
      e[i ^ 1].w += d;
      detla -= d;
      if (detla == 0) break;
    }
  }
  return flo - detla;
}
int dini() {
  int ans = 0;
  while (bfs(s)) {
    for (int i = 1; i <= t; i++) cur[i] = head[i];
    ans += dfs(s, INF);
  }
  return ans;
}
vector<vector<int>> ans;
int main() {
  int n1, n2, m;
  scanf("%d %d %d", &n1, &n2, &m);
  s = n1 + n2 + 1, t = n1 + n2 + 2;
  for (int i = 1; i <= m; i++) {
    int a, b;
    scanf("%d %d", &a, &b);
    b += n1;
    add_edge(a, b, 1);
    in[a]++;
    in[b]++;
  }
  int now = cnt, mx = INF;
  for (int i = 1; i <= n1 + n2; i++) mx = min(mx, in[i]);
  for (int i = 1; i <= n1; i++) add_edge(s, i, in[i] - mx);
  for (int i = n1 + 1; i <= n1 + n2; i++) add_edge(i, t, in[i] - mx);
  for (int i = mx; i >= 0; i--) {
    dini();
    vector<int> res;
    for (int j = 3; j <= now; j += 2) {
      if (e[j].w == 0) {
        res.push_back(j / 2);
      }
    }
    ans.push_back(res);
    for (int i = 1; i <= n1; i++) add_edge(s, i, 1);
    for (int i = n1 + 1; i <= n1 + n2; i++) add_edge(i, t, 1);
  }
  reverse(ans.begin(), ans.end());
  int siz = ans.size();
  for (int i = 0; i < siz; i++) {
    int si = ans[i].size();
    printf("%d", si);
    for (int j = 0; j < si; j++) printf(" %d", ans[i][j]);
    putchar('\n');
  }
  return 0;
}
