main = do
putStrLn $ f
["ABCDE", "a c", "123 567"];
f[]=[]
f x=[h|h:_<-x]++f[t|_:t<-x]
bWFpbiA9IGRvCiAgICBwdXRTdHJMbiAkIGYgWyJTSU1QTEUiXTsKCXB1dFN0ckxuICQgZiBbIlBPTExTIiwgIkVQRUVTIl07CglwdXRTdHJMbiAkIGYgWyJMWUVTIiwgIkFQUk9OUyJdOwogICAgcHV0U3RyTG4gJCBmIFsiQUJDREUiLCAiYSBjIiwgIjEyMyA1NjciXTsKICAgIHB1dFN0ckxuICQgZiBbIlwiXG4kPyoiLCAiIiwgIiwoLilcXCJdCgpmW109W10KZiB4PVtofGg6XzwteF0rK2ZbdHxfOnQ8LXhd