#Curses nie działa więc to się nadae tylko do zadań ze spoja :P
#loops of whole input
blocks_no = int(input())
patterns = []
for i in range(blocks_no):
patterns.append(input())
for pattern in patterns:
rows = int(pattern[0])
columns = int(pattern[2])
for r in range(rows):
if r % 2 != 0:
print("".join([".", "*"]*columns)[:columns])
else:
print("".join(["*", "."]*columns)[:columns])
print("")
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