function main(input) {
  var n = input[0]-0;
  var s = input[1].split(" ")[0];
  var t = input[1].split(" ")[1];
  var ans = "";
  for(var i=0;i<n;i++){
    ans += s[i] + t[i];
  }
  console.log(ans);
}
main(require('fs').readFileSync('/dev/stdin', 'utf8').trim().split("\n"))
