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.
from os import path
from sys import stdin, stdout


filename = "../templates/input.txt"
if path.exists(filename):
    stdin = open(filename, 'r')


def input():
    return stdin.readline().rstrip()


def print(*args, sep=' ', end='\n'):
    stdout.write(sep.join(map(str, args)))
    stdout.write(end)


def solution():
    n, m, k = [int(num) for num in input().split()]
    points = []
    dj = -1
    j = -1
    for i in range(n):
        dj = -dj
        j += dj
        while 0 <= j <= m - 1:
            points.append((i, j))
            j += dj
    for i in range(k - 1):
        print(2, points[2 * i][0] + 1, points[2 * i][1] + 1, points[2 * i + 1][0] + 1, points[2 * i + 1][1] + 1)
    print(len(points) - 2 * (k - 1), end=' ')
    for i in range(2 * k - 2, len(points)):
        print(points[i][0] + 1, points[i][1] + 1, end=' ')


def main():
    t = 1
    while t:
        solution()
        t -= 1


if __name__ == '__main__':
    main()
