#include using namespace std; using i64 = long long; #define rep(i, s, e) for (int(i) = (s); (i) <= (e); (i)++) int main() { i64 N; cin >> N; i64 K = 0; string all = "qwertyuiopasdfghjklzxcvbnm"; int idx = 0; string ans = "qwqw"; if (N == 1) { cout << "a" << endl; return 0; } int i = 31; while (!(N & (1LL << i))) i--; i--; idx = 2; bool first = true; for (; i >= 0; i--) { if (!first) { ans = ans[1] + ans; ans = ans[1] + ans; ans = ans + ans[0] + ans[1]; } first = false; if (N & (1LL << i)) { ans = string() + all[idx] + all[idx + 1] + ans + all[idx] + all[idx + 1]; idx += 2; if(idx + 1 >= all.size()) idx = 1; } } cout << ans << endl; }