#include <bits/stdc++.h>
using namespace std;
int visited[301][301];
vector<pair<int, int> > v[90002];
void solve(int x, int y, int n, int m, int k, int done) {
  visited[x][y] = 1;
  v[done].push_back(make_pair(x, y));
  if (done < k && v[done].size() == 2) {
    done++;
  }
  if ((y + 1) <= m && !visited[x][y + 1]) {
    solve(x, y + 1, n, m, k, done);
  }
  if ((y - 1) >= 1 && visited[x][y - 1] == 0) {
    solve(x, y - 1, n, m, k, done);
  }
  if ((x + 1) <= n && visited[x + 1][y] == 0) {
    solve(x + 1, y, n, m, k, done);
  }
}
int main() {
  int n, m, k;
  memset(visited, 0, sizeof(visited));
  scanf("%d %d %d", &n, &m, &k);
  int i;
  solve(1, 1, n, m, k, 1);
  for (i = 1; i <= k; i++) {
    printf("%d ", v[i].size());
    for (int j = 0; j < v[i].size(); j++) {
      printf("%d %d ", v[i][j].first, v[i][j].second);
    }
    printf("\n");
  }
  return 0;
}
