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.
def addX(x, y):
    if y % 2 == 0:
        x += 1
        if x == m:
            y += 1
            x -= 1
    else:
        x -= 1
        if x == -1:
            y += 1
            x += 1
    return x, y

n, m, k = [int(x) for x in input().split()]
res = []
curx, cury, curk, curlen = 0, 0, 0, 0
for i in range(k-1):
    res.append([])
    for j in range(2):
        res[i].append([cury+1, curx+1])
        curx, cury = addX(curx, cury)
res.append([])
while cury < n:
    res[k-1].append([cury+1, curx+1])
    curx, cury = addX(curx, cury)
print('\n'.join(str(len(x)) + ' ' + ' '.join(' '.join(list(map(str, y))) for y in x) for x in res))
#print(res)
