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())

rt=[[]]

for i in range(m):
    if i%2==0:  # down -> up
        for j in range(n,0,-1):
            rt[-1].append([i+1,j])
    else:
        for j in range(n):
            rt[-1].append([i+1,j+1])
k-=1

for i in range(m):
    if k==0:
        break
    if i % 2 == 0:  # down -> up
        for j in range(n//2):
            rt.append([rt[0][0], rt[0][1]])
            del (rt[0][0])
            del (rt[0][0])
            k-=1
            if k==0:
                break
        if k!=0 and n%2==1:
            rt.append([rt[0][0],rt[0][1]])
            del(rt[0][0])
            del(rt[0][0])
            k-=1
    else:
        for j in range(n//2):
            rt.append([rt[0][0], rt[0][1]])
            del (rt[0][0])
            del (rt[0][0])
            k-=1

for i in range(len(rt)):
    print(len(rt[i]),end=" ")
    for j in range(len(rt[i])):
        print(rt[i][j][0],rt[i][j][1],end=" ")
    print()