#include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include using namespace std; typedef long long ll; typedef unsigned int ui; const ll mod = 1000000007; const ll INF = (ll)1000000007 * 1000000007; typedef pair P; #define stop char nyaa;cin>>nyaa; #define rep(i,n) for(int i=0;i=0;i--) #define Rep(i,sta,n) for(int i=sta;i=sta;i--) #define rep1(i,n) for(int i=1;i<=n;i++) #define per1(i,n) for(int i=n;i>=1;i--) #define Rep1(i,sta,n) for(int i=sta;i<=n;i++) typedef long double ld; const ld eps = 1e-8; const ld pi = acos(-1.0); typedef pair LP; int n; void solve(){ cin >> n; ll k=0; while((k+1)*(k+2)/2<=n){ k+=1; } ll m=n-k*(k+1)/2; rep(i,k){ cout << "a" << ""; } rep(i,m){ cout << (char)(i%25+'b') << ""; } cout << "" << endl; } int main(){ ios::sync_with_stdio(false); cin.tie(0); cout << fixed << setprecision(50); solve(); }