first = int(input())
second = int(input())
max_pw = int(input())

counter = 0
A = 35
B = 64
is_enough = False
for x in range(1, first+1):
     for y in range(1, second+1):
         print(f"{chr(A)}{chr(B)}{x}{y}{chr(B)}{chr(A)}", end="|")
         counter += 1
         A += 1
         if A > 55:
             A = 35
         B += 1
         if B > 96:
             B = 64
         if counter >= max_pw:
             is_enough = True
             break
     if is_enough:
         break