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.
# import sys
# sys.stdin = open("F:\\Scripts\\input","r")
# sys.stdout = open("F:\\Scripts\\output","w")


MOD = 10**9 + 7
I = lambda:list(map(int,input().split()))

def pr(x,ys,ye):
	for i in range(ys , ye + 1):
		print(x,i,end = ' ')
	print("")

n, m, k = I()
x = 1
y = 1
rev = False
for i in range(1,k):
	print(2,x,y,end=" ")
	if rev:
		y -= 1
		if y == 0:
			x += 1
			y = 1
			rev = False
	else:
		y += 1
		if y > m:
			x += 1
			y = m
			rev = True
	print(x,y)
	if rev:
		y -= 1
		if y == 0:
			x += 1
			y = 1
			rev = False
	else:
		y += 1
		if y > m:
			x += 1
			y = m
			rev = True
print((n - x)*m + m - y + 1,end = ' ')
while 1 <= y <= m:
	print(x,y,end=' ')
	if rev:
		y -= 1
	else:
		y += 1
for i in range(x+1,n+1):
	for k in range(1 , m + 1):
		print(i,k,end = ' ')
	