slom

#include <iostream>
using namespace std;
int main() {
	ios_base::sync_with_stdio(0);
	cin.tie(0);
	int x, n;
	string s, os;
	cin >> x >> s;
	n = s.size();
	os = s;
	int c = 0;
	do {
		c++;
		string ns = s;
		for (int i = 0; i < n; i+=2) {
			ns[i/2] = s[i];
		}
		for (int i = 1, j = n-1; i < n; i+=2, --j) {
			ns[j] = s[i];
		}
		s = ns;
	} while (os != s);
	x %= c;
	s = os;
	for (int xi = 0; xi < x; ++xi) {
		string ns = s;
		for (int i = 0; i < n; i+=2) {
			ns[i/2] = s[i];
		}
		for (int i = 1, j = n-1; i < n; i+=2, --j) {
			ns[j] = s[i];
		}
		s = ns;
	}
	cout << s;
}

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