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.
lst = list(map(int, input().split(' ')))
n, m, k = lst

coors = []
col = 1
mode = 1 # 1 == inc, 0 == dec
for i in range(1, n + 1):
	if(col > m):
		col = m
	if(col < 1):
		col = 1
	while(col <= m and col >= 1):
		coors.append([i, col])
		if(mode == 1):
			col += 1
		else:
			col -= 1
	if(mode == 0):
		mode = 1
	else:
		mode = 0
quo = (n * m) // k
rem = (n * m) % k
t = 0
for i in range(k - 1):
	print(quo, end=' ', sep = ' ')
	for i in range(quo):
		print(coors[i + t][0], end=' ', sep = ' ')
		print(coors[i + t][1], end=' ', sep = ' ')
	t += quo
	print()

print(quo + rem, end=' ', sep = ' ')
for i in range(quo + rem):
	print(*coors[i + t], end=' ', sep = ' ')
