function main(input) {
  const tmp = input.trim().split('\n')
  const n = parseInt(tmp[0], 10)
  const tmp2 = tmp[1].split(' ')
  const s = tmp2[0]
  const t = tmp2[1]

  let answer = ''
  for (let i = 0; i < n; i++) {
    answer += s[i] + t[i]
  }
  console.log(answer)
}
main(require('fs').readFileSync('/dev/stdin', 'utf8'))