557 B | 557 chars
import sys
from math import sqrt, pi, sin, factorial
inp = lambda : sys.stdin.readline()[:-1].strip()
mii = lambda x = " " : [*map(int,inp().split(x))]
mfi = lambda x = " " : [*map(float,inp().split(x))]
ii = lambda : int(inp())
fi = lambda : float(inp())
p = print
def solve():
r, c = mii()
print(".."+"+-"*(c - 1)+"+")
print(".."+"|."*(c - 1)+"|")
for i in range(r - 1):
print("+-"*c+"+")
print("|."*c+"|")
print("+-"*c+"+")
if __name__ == "__main__":
tc = ii()
for t in range(1, tc+1):
print(f"Case #{t}:")
ret = solve()