'use strict';
const main = input => {
  let n = input[0], words = input[1].split(' '), s = words[0], t = words[1], ans = '';
  
  for(let i=0; i<n; i++) {
    ans += s[i];
    ans += t[i];
  }
  console.log(ans);
  
}
main(require("fs").readFileSync("/dev/stdin", "utf8").split('\n'));