Palindromi

#include "bits/stdc++.h"

typedef long long ll;

using namespace std;

int main() {
    // palindrome
    int n;
    int k;
    cin >> n;
    cin >> k;
    string p;
    for (int i = 0; i< k; ++i) {
        p += 'a';
    }
    //cout << p;
    string r;
    vector<char> ch = {'b', 'c', 'd', 'e', 'f', 'g', 'h', 'i', 'j',
     'k', 'l', 'm', 'n', 'o', 'p', 'q', 'r', 's', 't', 'u', 'v', 'w', 'x', 'y','z'};
    for (int i = 0; i <= n-k; ++i) {
        if(r.size() == 0) {
            r = ch[i % ch.size()-1];
        } else {
            r += ch[i % ch.size()-1];
        }
    }
    //cout << r << endl;
    //cout << p.size() << endl;
    p += r;
    cout << p << '\n';
    //cout << p.size() << endl;
    return 0;
}

Test 1

Verdict: WRONG ANSWER

Test 2

Verdict: WRONG ANSWER

Test 3

Verdict: WRONG ANSWER

Test 4

Verdict: WRONG ANSWER

Test 5

Verdict: WRONG ANSWER

Test 6

Verdict: WRONG ANSWER

Test 7

Verdict: WRONG ANSWER

Test 8

Verdict: WRONG ANSWER

Test 9

Verdict: WRONG ANSWER

Test 10

Verdict: WRONG ANSWER

Test 11

Verdict: WRONG ANSWER

Test 12

Verdict: WRONG ANSWER

Test 13

Verdict: WRONG ANSWER

Test 14

Verdict: WRONG ANSWER

Test 15

Verdict: WRONG ANSWER

Test 16

Verdict: WRONG ANSWER

Test 17

Verdict: WRONG ANSWER