t={}i=-2
for l in io.lines()do
i=i+1
for j=1,#l do
s=t[i-j]or''t[i-j]=s..(' '):rep((i+j)*2-#s)..l:sub(j,j)end
end
for i=-51,6 do
i=t[i]and print(t[i])end