#include #include #include #include using namespace std; typedef long long ll; typedef vector vint; typedef pair pint; typedef vector vpint; #define rep(i,n) for(int i=0;i<(n);i++) #define reps(i,f,n) for(int i=(f);i<(n);i++) #define each(it,v) for(__typeof((v).begin()) it=(v).begin();it!=(v).end();it++) #define all(v) (v).begin(),(v).end() #define pb push_back #define mp make_pair #define fi first #define se second #define chmax(a, b) a = (((a)<(b)) ? (b) : (a)) #define chmin(a, b) a = (((a)>(b)) ? (b) : (a)) const int MOD = 1e9 + 7; const int INF = 1e9; int n; int cnt = 0; string s = ""; void pri(int t){ s += 'a' + 2 * cnt; s += 'b' + 2 * cnt; s += 'a' + 2 * cnt; rep(i, t - 1){ s += 'b' + 2 * cnt; s += 'a' + 2 * cnt; } return; } void pri2(int t, int nokori){ string s = "iwi"; rep(i, t - 1){ s += "wi"; } rep(i, nokori){ if(i % 3 == 1) s += 'a'; else if(i % 3 == 2) s += 'b'; else s += 'c'; } cout << s << endl; } int main(void){ cin >> n; if(n == 1){ cout << "a" << endl; }else if(n == 2){ cout << "ab" << endl; }else if(n == 3){ cout << "abc" << endl; }else{ while(n > 0){ int i = 0; int len = 1; while(i * i + len <= n && n >= 4){ i++; len += 2; } // printf("i %d\n", i); if(i != 0){ pri(i - 1); cnt++; // printf("%d %d %d\n", n, i, len); n -= (i - 1) * (i - 1) + len - 2; // printf("%d \n", n); }else{ break; } } rep(i, n){ if(i % 3 == 0) s += 'x'; else if(i % 3 == 1) s += 'y'; else s += 'z'; } } cout << s << endl; return 0; }