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 num_list = []

  if n % 2 == 1
    call add(num_list, 7)
    let n -= 3
  endif

  while n > 0
    call add(num_list, 1)
    let n -= 2
  endwhile
  let r = join(num_list, '')

  call o.append(r)
  return o.build()
endfunction

let s:input = getline(1, '$')
enew
put =s:main(s:input)
2,$print