c=("").char
w=io.write
for k=1,49 do
k=math.min(50-k,k)if k%15~=4 then
for i=1,k/2 do w(c(k/2-i<.6 and 92-k or 91-i*2))end
for i=1,26-k+k%2 do w(c(64+i))end
for i=(k-k%2)/2,1,-1 do w(c(k/2-i<.6 and 91-k+k%2*2 or 92-i*2))end
w"\n"end
end
Note that non-ascii characters in the above source code will be escaped (such as \x9f).