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.
def main():
    n, m, k = list(map(int, input().split()))
    ans = []
    if k == 1:
        for i in range(n):
            if i % 2 == 0:
                for j in range(m):
                    ans.append([i+1, j+1])
            else:
                for j in range(m-1, -1, -1):
                    ans.append([i+1, j+1])
        print(len(ans), end=' ')
        for i in range(len(ans)):
            print(ans[i][0], ans[i][1], end=' ')
    else:
        row,dir, col = 0, 0, 0
        while k > 1:
            if col + 2 <= m and dir == 0:
                ans.append([[row+1, col+1], [row+1, col+2]])
                col += 2
                k -= 1
            elif col + 2 == m+1 and dir == 0:
                ans.append([[row+1, col+1], [row+2, col+1]])
                row += 1
                dir = 1
                k-=1
                col-=1
            elif col + 2 == m+2 and dir == 0:
                row += 1
                col = 0
            elif col - 1 >= 0 and dir == 1:
                ans.append([[row+1, col+1], [row+1, col]])
                col -= 2
                k-=1
            elif col - 1 == -1 and dir == 1:
                ans.append([[row+1, col+1], [row+2, col+1]])
                k -= 1
                dir = 0
                row += 1
                col += 1
            elif col - 1 == -2 and dir == 1:
                row += 1
                dir = 0
        curr = []
        if dir == 0:
            c = col
            while c < m:
                curr.append([row+1, c+1])
                c+=1
            for i in range(row+1, n, 1):
                if (i - row - 1) % 2 == 0:
                    for j in range(m-1, -1, -1):
                        curr.append([i+1, j+1])
                else:
                    for j in range(m):
                        curr.append([i+1, j+1])
            ans.append(curr)
        else:
            c = col
            curr = []

            while c >= 0:
                curr.append([row+1, c+1])
                c-=1
            for i in range(row+1, n, 1):
                if (i - row - 1) % 2 == 0:
                    for j in range(m):
                        curr.append([i+1, j+1])
                else:
                    for j in range(m-1, -1, -1):
                        curr.append([i+1, j+1])
            ans.append(curr)
        for i in range(len(ans)):
            print(len(ans[i]), end=' ')
            for j in range(len(ans[i])):
                print(ans[i][j][0], ans[i][j][1], end=' ')
            print()


if __name__ == "__main__":
    main()
