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 = list( map( int, input().split() ) )

und = True
for i in range(k-1):
    und = False
    print( m, end='' )
    for j in range( m ):
        print( " %d %d" % (i+1,j+1), end='' )
    print()

p = []
j = 0
fl = True
if und == False:
    i += 1
else:
    i = 0
#print( 'i :=', i)
while i < n:

    if fl:
        while j < m:
            p.append( (i,j) )
            j += 1
        j = m-1
    else:
        while j >= 0:
            p.append( (i,j) )
            j -= 1
        j = 0
    fl = not fl

    i += 1

print( len(p), end='' )
for j in range( len(p) ):
    print( " %d %d" % ( p[j][0]+1,p[j][1]+1), end='' )
print()

#print( n, m, k )
