#include <bits/stdc++.h>
using namespace std;
bool vs[305][305], f;
int n, m, k, i, j, cnt;
int main() {
  std::ios::sync_with_stdio(false);
  i = 1, j = 1;
  cin >> n >> m >> k;
  while (k != 1) {
    if (j + 1 <= m) {
      cnt += 2;
      cout << 2 << " " << i << " " << j << " " << i << " " << j + 1 << endl;
      vs[i][j + 1] = 1;
      vs[i][j] = 1;
      j += 2;
      k--;
    } else {
      i++;
      j = 1;
    }
    if (i > n) break;
  }
  int z = 1;
  while (k != 1) {
    cout << 2 << " " << z << " " << m << " " << z + 1 << " " << m << endl;
    vs[z][m] = 1;
    vs[z + 1][m] = 1;
    z += 2;
    cnt += 2;
    k--;
  }
  cout << n * m - cnt;
  if (m % 2 == 0) {
    int a, b;
    a = n, b = m;
    while (b != 0) {
      if (b % 2 == 0) {
        a = n;
        while (a >= 1 && vs[a][b] == 0) {
          cout << " " << a << " " << b;
          a--;
        }
      } else {
        a = 1;
        while (a <= n && vs[a][b] == 1) {
          a++;
        }
        for (a; a <= n; a++) {
          cout << " " << a << " " << b;
        }
      }
      b--;
    }
  } else {
    int a, b;
    a = n, b = m;
    while (b > 0) {
      if (b % 2 == 0) {
        a = n;
        while (a >= 1 && vs[a][b] == 0) {
          cout << " " << a << " " << b;
          a--;
        }
      } else {
        a = 1;
        while (a <= n && vs[a][b] == 1) {
          a++;
        }
        for (a; a <= n; a++) cout << " " << a << " " << b;
      }
      b--;
    }
  }
  return 0;
}
