function! s:output() let this = {'lines': []} function! this.append(line) abort call add(self.lines, a:line) endfunction function! this.build() abort return join(self.lines, "\n") endfunction return this endfunction function! s:main(input) abort let o = s:output() let n = str2nr(a:input[0]) let r = (n % 2 == 0) ? n : n + 1 call o.append(r) return o.build() endfunction let s:input = getline(1, '$') enew put =s:main(s:input) 2,$print