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.
n, m, k = map(int, input().split())
c = k
dir = "right"
start_x = 1
start_y = 1
ans = []
while c > 0:

    if c == 1:
        r = m*n-2*(k-1)
        s = str(r)+' '
        pos = []
        while r > 0:
            pos.append((start_y, start_x))
            move = 1 if dir == "right" else -1
            start_x += move
            if start_x == m+1:
                start_x = m
                start_y += 1
                dir = "left"
            if start_x == 0:
                start_x = 1
                start_y += 1
                dir = "right"
            r -= 1
        s += ' '.join(["{} {}".format(x[0],x[1]) for x in pos])
        ans.append(s)
    else:
        move = 2 if dir == "right" else -2
        if dir == "right":
            if start_x + move > m+1:
                ans.append("2 {} {} {} {}".format(start_y, start_x, start_y+1, start_x))
                start_x = m
                start_y += 1
                move -= 1
                dir = "left"
                start_x -= 1
            else:
                ans.append("2 {} {} {} {}".format(start_y, start_x, start_y, start_x+1))
                start_x += 2
                if start_x > m:
                    start_y += 1
                    start_x = m
                    dir = "left"
        else:
            if start_x + move < 0:
                ans.append("2 {} {} {} {}".format(start_y, start_x, start_y+1, start_x))
                start_x = 1
                start_y += 1
                move -= 1
                dir = "right"
                start_x += 1
            else:
                ans.append("2 {} {} {} {}".format(start_y, start_x, start_y, start_x-1))
                start_x -= 2
                if start_x < 1:
                    start_y += 1
                    start_x = 1
                    dir = "right"
    c -= 1


print(*ans, sep='\n')