#include<bits/stdc++.h> #define rep(i,a,b) for(int i=a;i<b;i++) #define rrep(i,a,b) for(int i=a;i>=b;i--) #define fore(i,a) for(auto &i:a) #pragma GCC optimize ("-O3") using namespace std; void _main(); int main() { cin.tie(0); ios::sync_with_stdio(false); _main(); } //--------------------------------------------------------------------------------------------------- /*--------------------------------------------------------------------------------------------------- ∧_∧ ∧_∧ (´<_` ) Welcome to My Coding Space! ( ´_ゝ`) / ⌒i / \ | | / / ̄ ̄ ̄ ̄/ | __(__ニつ/ _/ .| .|____ \/____/ (u ⊃ ---------------------------------------------------------------------------------------------------*/ //--------------------------------------------------------------------------------------------------- void _main() { int N; cin >> N; string ans = ""; char c = 'a'; N--; while (N) { if (N % 2) c++, ans = c + ans + c, N--; else ans = c + ans + c, N /= 2; } cout << ans << endl; }