Valera has got a rectangle table consisting of *n* rows and *m* columns. Valera numbered the table rows starting from one, from top to bottom and the columns – starting from one, from left to right. We will represent cell that is on the intersection of row *x* and column *y* by a pair of integers (*x*, *y*).

Valera wants to place exactly *k* tubes on his rectangle table. A tube is such sequence of table cells (*x*<sub class="lower-index">1</sub>, *y*<sub class="lower-index">1</sub>), (*x*<sub class="lower-index">2</sub>, *y*<sub class="lower-index">2</sub>), ..., (*x*<sub class="lower-index">*r*</sub>, *y*<sub class="lower-index">*r*</sub>), that: 
 -  *r* ≥ 2; -  for any integer *i* (1 ≤ *i* ≤ *r* - 1) the following equation |*x*<sub class="lower-index">*i*</sub> - *x*<sub class="lower-index">*i* + 1</sub>| + |*y*<sub class="lower-index">*i*</sub> - *y*<sub class="lower-index">*i* + 1</sub>| = 1 holds; -  each table cell, which belongs to the tube, must occur exactly once in the sequence. 
Valera thinks that the tubes are arranged in a fancy manner if the following conditions are fulfilled: 
 -  no pair of tubes has common cells; -  each cell of the table belongs to some tube. 
Help Valera to arrange *k* tubes on his rectangle table in a fancy manner.
The first line contains three space-separated integers *n*, *m*, *k* (2 ≤ *n*, *m* ≤ 300; 2 ≤ 2*k* ≤ *n*·*m*) — the number of rows, the number of columns and the number of tubes, correspondingly.
'''input
3 3 4
'''
# I am Mr.Inconsistent 
from sys import stdin
import math


def print_special(pcount, i, j):

	if pcount == 0:
		if i == 1 and j == 1:
			print(2, end = ' ')
		else:
			print('\n2' , end= ' ')

def final_param(last_i,last_j, m, n):
	if last_i % 2 == 0:
		if last_j == 1:
			return last_i + 1, 1
		else:
			return last_i, last_j - 1
	else:
		if last_j == n:
			return last_i + 1, n
		else:
			return last_i, last_j + 1


def print_initial(m, n, k):
		pcount = 0
		for i in range(1, m + 1):
			if i % 2 == 0:
				for j in range(n, 0, -1):
					if k == 1:
						print()
						return final_param(last_i, last_j, m, n)
					print_special(pcount, i, j)
					last_i, last_j = i, j
					print(i, j, end = ' ')
					pcount += 1
					pcount %= 2
					if pcount == 0:
						k -= 1
			else:
				for j in range(1, n + 1):
					if k == 1:
						print()
						return final_param(last_i, last_j,m, n)
					print_special(pcount, i, j)
					last_i, last_j = i, j
					print(i, j, end = ' ')
					pcount += 1
					pcount %= 2
					if pcount == 0:
						k -= 1


def print_final(last_i, last_j, m, n):

	print(m * n - 2 *( k - 1), end = ' ')
	# partial line remain
	if last_i % 2 == 0:
		for j in range(last_j, 0, -1):
			print(last_i, j, end = ' ')
	else:
		for j in range(last_j, n + 1):
			print(last_i, j, end = ' ')

	# full remain
	for i in range(last_i + 1, m + 1):
		if i % 2 == 0:
			for j in range(n, 0, -1):
				print(i, j, end = ' ')
		else:
			for j in range(1, n + 1):
				print(i, j, end = ' ')


# main starts
m, n,  k = list(map(int, stdin.readline().split()))

i = 1;
j = 1
last_i, last_j = print_initial(m, n, k)	
print_final(last_i, last_j, m, n)	