const main = arg => {
  const lines = arg.split("\n");
  const N = parseInt(arg[0]);
  const [S,T] = arg[1].split(" ");
  
  let answer = "";
  for (let i=0; i<N; i++) {
    answer += S[i] + T[i]
  }
  console.log(answer)
}

main(require('fs').readFileSync('/dev/stdin', 'utf8'));  