Merkkijono

const readline = require("readline");

const r = readline.createInterface({
  input: process.stdin,
  output: process.stdout,
  terminal: false
});

function add(str, chr) {
  return chr + str.split("").map(c => c + chr).join("");
};

r.on("line", (line) => {
  const n = parseInt(line);
  let ans = "";
  for (let i = 0; i < n; i++) {
    ans = add(ans, String.fromCharCode(97 + i));
  }
  console.log(ans);
  process.exit(0);
});

Test 1

Verdict: ACCEPTED

Test 2

Verdict: ACCEPTED

Test 3

Verdict: ACCEPTED

Test 4

Verdict: ACCEPTED

Test 5

Verdict: ACCEPTED

Test 6

Verdict: ACCEPTED

Test 7

Verdict: ACCEPTED

Test 8

Verdict: ACCEPTED

Test 9

Verdict: ACCEPTED

Test 10

Verdict: ACCEPTED

Test 11

Verdict: ACCEPTED

Test 12

Verdict: ACCEPTED

Test 13

Verdict: ACCEPTED

Test 14

Verdict: ACCEPTED

Test 15

Verdict: ACCEPTED

Test 16

Verdict: ACCEPTED