Merkkijono

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

function merkkijono(n) {
    const abc = 'abcdefghijklmnopqrstuvwxyz';
    let result = [];
    for (let i = 0; i < n; i++) {
        const c = abc[i];
        result = [...result.flatMap(v => [c, v]), c];
    }
    console.log(result.join(''));
}

r.on('line', function (line) {
    merkkijono(parseInt(line));
});

Test 1

Verdict: RUNTIME ERROR

/box/input/code.js:13
        result = [...result.flatMap(v => [c, v]), c];...

Test 2

Verdict: RUNTIME ERROR

/box/input/code.js:13
        result = [...result.flatMap(v => [c, v]), c];...

Test 3

Verdict: RUNTIME ERROR

/box/input/code.js:13
        result = [...result.flatMap(v => [c, v]), c];...

Test 4

Verdict: RUNTIME ERROR

/box/input/code.js:13
        result = [...result.flatMap(v => [c, v]), c];...

Test 5

Verdict: RUNTIME ERROR

/box/input/code.js:13
        result = [...result.flatMap(v => [c, v]), c];...

Test 6

Verdict: RUNTIME ERROR

/box/input/code.js:13
        result = [...result.flatMap(v => [c, v]), c];...

Test 7

Verdict: RUNTIME ERROR

/box/input/code.js:13
        result = [...result.flatMap(v => [c, v]), c];...

Test 8

Verdict: RUNTIME ERROR

/box/input/code.js:13
        result = [...result.flatMap(v => [c, v]), c];...

Test 9

Verdict: RUNTIME ERROR

/box/input/code.js:13
        result = [...result.flatMap(v => [c, v]), c];...

Test 10

Verdict: RUNTIME ERROR

/box/input/code.js:13
        result = [...result.flatMap(v => [c, v]), c];...

Test 11

Verdict: RUNTIME ERROR

/box/input/code.js:13
        result = [...result.flatMap(v => [c, v]), c];...

Test 12

Verdict: RUNTIME ERROR

/box/input/code.js:13
        result = [...result.flatMap(v => [c, v]), c];...

Test 13

Verdict: RUNTIME ERROR

/box/input/code.js:13
        result = [...result.flatMap(v => [c, v]), c];...

Test 14

Verdict: RUNTIME ERROR

/box/input/code.js:13
        result = [...result.flatMap(v => [c, v]), c];...

Test 15

Verdict: RUNTIME ERROR

/box/input/code.js:13
        result = [...result.flatMap(v => [c, v]), c];...

Test 16

Verdict: RUNTIME ERROR

/box/input/code.js:13
        result = [...result.flatMap(v => [c, v]), c];...