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 = input().split()
n = int(n)
m = int(m)
k = int(k)
lst1 = []

i1 = 0
i2 = n-1
j1 = 0
j2 = m-1
while(i1 < i2 and j1 < j2):
    for i in range(j1,j2+1,1):
        lst1.append([i1,i])
    
    i1+=1
    for i in range(i1,i2+1,1):
        lst1.append([i,j2])
    
    j2-=1
    
    for i in range(j2,j1-1,-1):
        lst1.append([i2,i])
        
    i2-=1
    
    for i in range(i2,i1-1,-1):
        lst1.append([i,j1])
    
    j1+=1

# print(i1)
# print(i2)
# print(j1)
# print(j2)

if i1 == i2 and j1 == j2:
    lst1.append([i1,j1])
elif i1 == i2 and j1 < j2:
    for i in range(j1,j2,1):
        lst1.append([i1,i])
elif j1 == j2 and i1 < i2:
    for i in range(i1,i2,1):
        lst1.append([i,j1])

# print(lst1)
i = 0
while(i < 2*k-2):
    print(2,end = ' ')
    print(lst1[i][0]+1,end = ' ')
    print(lst1[i][1]+1,end = ' ')
    i+=1
    print(lst1[i][0]+1,end = ' ')
    print(lst1[i][1]+1)
    i+=1
    
print(n*m-2*k+2,end = ' ')
for j in range(i,n*m):
    print(lst1[j][0]+1,end = ' ')
    print(lst1[j][1]+1,end = ' ')
