import std.conv, std.functional, std.range, std.stdio, std.string;
import std.algorithm, std.array, std.bigint, std.bitmanip, std.complex, std.container, std.math, std.mathspecial, std.numeric, std.regex, std.typecons;
import core.bitop;

class EOFException : Throwable { this() { super("EOF"); } }
string[] tokens;
string readToken() { for (; tokens.empty; ) { if (stdin.eof) { throw new EOFException; } tokens = readln.split; } auto token = tokens.front; tokens.popFront; return token; }
int readInt() { return readToken.to!int; }
long readLong() { return readToken.to!long; }

bool chmin(T)(ref T t, in T f) { if (t > f) { t = f; return true; } else { return false; } }
bool chmax(T)(ref T t, in T f) { if (t < f) { t = f; return true; } else { return false; } }

int binarySearch(alias pred, T)(in T[] as) { int lo = -1, hi = cast(int)(as.length); for (; lo + 1 < hi; ) { const mid = (lo + hi) >> 1; (unaryFun!pred(as[mid]) ? hi : lo) = mid; } return hi; }
int lowerBound(T)(in T[] as, T val) { return as.binarySearch!(a => (a >= val)); }
int upperBound(T)(in T[] as, T val) { return as.binarySearch!(a => (a > val)); }


debug {
  enum B = 3;
} else {
  enum B = 10^^4;
}

void main() {
  try {
    for (; ; ) {
      const M = readLong;
      
      if (M == 0) {
        writeln("a");
      } else {
        int[] ans;
        const q2 = (M - 1) / B;
        const r2 = (M - 1) % B + 1;
        if (q2 > 0) {
          const q1 = (q2 - 1) / B;
          const r1 = (q2 - 1) % B + 1;
          if (q1 > 0) {
            ans = 0.repeat(q1 - 1).array ~ 1.repeat(B).array;
          }
          ans = 1.repeat(r1 - 1).array ~ ans ~ 2.repeat(B).array;
        }
        ans = 2.repeat(r2 - 1).array ~ ans;
        ans = [0, 1, 2] ~ ans;
        writeln(ans.map!(a => "con"[a]).array);
        
        debug {
          int brt;
          foreach (i, a; ans) foreach (j, b; ans) foreach (k, c; ans) {
            if (i < j && j < k && a == 0 && b == 1 && c == 2) {
              ++brt;
            }
          }
          writefln("M = %s, brt = %s", M, brt);
          assert(M == brt);
        }
      }
    }
  } catch (EOFException e) {
  }
}