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
input = sys.stdin.readline
read_tuple = lambda _type: map(_type, input().split(' '))

def new_point_generator(n, m):
    i, j = 0, 0
    yield f"{i + 1} {j + 1}"
    while True:
        if j + 1 < m and i % 2 == 0:
            j += 1
        elif j - 1 >= 0 and i % 2 == 1:
            j -= 1
        yield f"{i + 1} {j + 1}"
        if j == m - 1 or j == 0:
            i += 1
            yield f"{i + 1} {j + 1}"

def solve():
    n, m, k = read_tuple(int)
    cells = n * m
    cells_for_pipe = [cells // k for _ in range(k)]
    cells_for_pipe[0] += cells % k
    cells_for_pipe = iter(cells_for_pipe)
    filled = 0
    point_generator = new_point_generator(n, m)
    while filled < cells:
        _len = next(cells_for_pipe)
        print(_len, end=' ')
        for _ in range(_len):
            print(next(point_generator), end=' ')
        filled += _len
        print()

if __name__ == '__main__':
    solve()