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.
# t=int(input())
# for _ in range(t):
rows,cols,k=map(int,input().split())
# arr=list(map(int,input().split()))
# # rows,cols=4,4
# # arr=[1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14 ,15, 16]
# mat=[]
spiralMat=[]
# for i in range(rows):
#     li=arr[i*cols:i*cols+cols]
#     mat.append(li)
# print(mat)

left=0
right=cols-1
up=0
down=rows-1

while(left<=right and up<=down):
    for i in range(left,right+1):
        # print(mat[up][i],end=" ")

        # spiralMat.append(mat[up][i])
        spiralMat.append((up+1,i+1))
    up+=1
    for i in range(up,down+1):
        # print(mat[i][right],end=" ")
        # spiralMat.append(mat[i][right])
        spiralMat.append((i+1,right+1))
    right-=1

    if(left<=right and up<=down):
        for i in range(right,left-1,-1):
            # print(mat[down][i],end=" ")
            # spiralMat.append(mat[down][i])
            spiralMat.append((down+1,i+1))
        down-=1

        for i in range(down,up-1,-1):
            # print(mat[i][left],end=" ")
            # spiralMat.append(mat[i][left])
            spiralMat.append((i+1,left+1))
        left+=1
# print(spiralMat)

n=rows*cols
index=0
for i in range(k-1):
    print(2,end=" ")
    for j in range(2):
        print(*spiralMat[index],end=" ")
        index+=1
    # print(*spiralMat[i*2:i*2+2])
    # index+=2
    print()
# print(n,index)

print((n- index),end=" ")
for i in range(index,n):
    print(*spiralMat[i],end=" ")
print()
# print((n- index-1),*spiralMat[index:n])
