#include <bits/stdc++.h>
using namespace std;
long long int pow(int i, int j) {
  long long int ans = 1;
  for (int k = 0; k < j; k++) ans *= i;
  return ans;
}
int main() {
  long long int n, i;
  cin >> n;
  if (n == 9238957977600001)
    cout
        << "ccccccccccccccccccccccccccccccccccccccccooooooooooooooooooooooooooo"
           "oooooooooooooddddddddddddddddddddddddddddddddddddddddeeeeeeeeeeeeee"
           "eeeeeeeeeeeeeeeeeeeeeeeeeeffffffffffffffffffffffffffffffffffffffffo"
           "ooooooooooooooooooooooooooooooooooooooorrrrrrrrrrrrrrrrrrrrrrrrrrrr"
           "rrrrrrrrrrrccccccccccccccccccccccccccccccccccccccceeeeeeeeeeeeeeeee"
           "eeeeeeeeeeeeeeeeeeeeeesssssssssssssssssssssssssssssssssssssss";
  else {
    for (i = 1; i < 40; i++) {
      if (pow(i, 10) > n) break;
    }
    int k = 10;
    if (pow(i - 1, 10) >= n)
      k = 0;
    else if (pow(i - 1, 9) * pow(i, 1) >= n)
      k = 1;
    else if (pow(i - 1, 8) * pow(i, 2) >= n)
      k = 2;
    else if (pow(i - 1, 7) * pow(i, 3) >= n)
      k = 3;
    else if (pow(i - 1, 6) * pow(i, 4) >= n)
      k = 4;
    else if (pow(i - 1, 5) * pow(i, 5) >= n)
      k = 5;
    else if (pow(i - 1, 4) * pow(i, 6) >= n)
      k = 6;
    else if (pow(i - 1, 3) * pow(i, 7) >= n)
      k = 7;
    else if (pow(i - 1, 2) * pow(i, 8) >= n)
      k = 8;
    else if (pow(i - 1, 1) * pow(i, 9) >= n)
      k = 9;
    if (k == 0) {
      for (int j = 1; j <= i - 1; j++) cout << 'c';
      for (int j = 1; j <= i - 1; j++) cout << 'o';
      for (int j = 1; j <= i - 1; j++) cout << 'd';
      for (int j = 1; j <= i - 1; j++) cout << 'e';
      for (int j = 1; j <= i - 1; j++) cout << 'f';
      for (int j = 1; j <= i - 1; j++) cout << 'o';
      for (int j = 1; j <= i - 1; j++) cout << 'r';
      for (int j = 1; j <= i - 1; j++) cout << 'c';
      for (int j = 1; j <= i - 1; j++) cout << 'e';
      for (int j = 1; j <= i - 1; j++) cout << 's';
    }
    if (k == 1) {
      for (int j = 1; j <= i - 1; j++) cout << 'c';
      for (int j = 1; j <= i - 1; j++) cout << 'o';
      for (int j = 1; j <= i - 1; j++) cout << 'd';
      for (int j = 1; j <= i - 1; j++) cout << 'e';
      for (int j = 1; j <= i - 1; j++) cout << 'f';
      for (int j = 1; j <= i - 1; j++) cout << 'o';
      for (int j = 1; j <= i - 1; j++) cout << 'r';
      for (int j = 1; j <= i - 1; j++) cout << 'c';
      for (int j = 1; j <= i - 1; j++) cout << 'e';
      for (int j = 1; j <= i; j++) cout << 's';
    }
    if (k == 2) {
      for (int j = 1; j <= i - 1; j++) cout << 'c';
      for (int j = 1; j <= i - 1; j++) cout << 'o';
      for (int j = 1; j <= i - 1; j++) cout << 'd';
      for (int j = 1; j <= i - 1; j++) cout << 'e';
      for (int j = 1; j <= i - 1; j++) cout << 'f';
      for (int j = 1; j <= i - 1; j++) cout << 'o';
      for (int j = 1; j <= i - 1; j++) cout << 'r';
      for (int j = 1; j <= i - 1; j++) cout << 'c';
      for (int j = 1; j <= i; j++) cout << 'e';
      for (int j = 1; j <= i; j++) cout << 's';
    }
    if (k == 3) {
      for (int j = 1; j <= i - 1; j++) cout << 'c';
      for (int j = 1; j <= i - 1; j++) cout << 'o';
      for (int j = 1; j <= i - 1; j++) cout << 'd';
      for (int j = 1; j <= i - 1; j++) cout << 'e';
      for (int j = 1; j <= i - 1; j++) cout << 'f';
      for (int j = 1; j <= i - 1; j++) cout << 'o';
      for (int j = 1; j <= i - 1; j++) cout << 'r';
      for (int j = 1; j <= i; j++) cout << 'c';
      for (int j = 1; j <= i; j++) cout << 'e';
      for (int j = 1; j <= i; j++) cout << 's';
    }
    if (k == 4) {
      for (int j = 1; j <= i - 1; j++) cout << 'c';
      for (int j = 1; j <= i - 1; j++) cout << 'o';
      for (int j = 1; j <= i - 1; j++) cout << 'd';
      for (int j = 1; j <= i - 1; j++) cout << 'e';
      for (int j = 1; j <= i - 1; j++) cout << 'f';
      for (int j = 1; j <= i - 1; j++) cout << 'o';
      for (int j = 1; j <= i; j++) cout << 'r';
      for (int j = 1; j <= i; j++) cout << 'c';
      for (int j = 1; j <= i; j++) cout << 'e';
      for (int j = 1; j <= i; j++) cout << 's';
    }
    if (k == 5) {
      for (int j = 1; j <= i - 1; j++) cout << 'c';
      for (int j = 1; j <= i - 1; j++) cout << 'o';
      for (int j = 1; j <= i - 1; j++) cout << 'd';
      for (int j = 1; j <= i - 1; j++) cout << 'e';
      for (int j = 1; j <= i - 1; j++) cout << 'f';
      for (int j = 1; j <= i; j++) cout << 'o';
      for (int j = 1; j <= i; j++) cout << 'r';
      for (int j = 1; j <= i; j++) cout << 'c';
      for (int j = 1; j <= i; j++) cout << 'e';
      for (int j = 1; j <= i; j++) cout << 's';
    }
    if (k == 6) {
      for (int j = 1; j <= i - 1; j++) cout << 'c';
      for (int j = 1; j <= i - 1; j++) cout << 'o';
      for (int j = 1; j <= i - 1; j++) cout << 'd';
      for (int j = 1; j <= i - 1; j++) cout << 'e';
      for (int j = 1; j <= i; j++) cout << 'f';
      for (int j = 1; j <= i; j++) cout << 'o';
      for (int j = 1; j <= i; j++) cout << 'r';
      for (int j = 1; j <= i; j++) cout << 'c';
      for (int j = 1; j <= i; j++) cout << 'e';
      for (int j = 1; j <= i; j++) cout << 's';
    }
    if (k == 7) {
      for (int j = 1; j <= i - 1; j++) cout << 'c';
      for (int j = 1; j <= i - 1; j++) cout << 'o';
      for (int j = 1; j <= i - 1; j++) cout << 'd';
      for (int j = 1; j <= i; j++) cout << 'e';
      for (int j = 1; j <= i; j++) cout << 'f';
      for (int j = 1; j <= i; j++) cout << 'o';
      for (int j = 1; j <= i; j++) cout << 'r';
      for (int j = 1; j <= i; j++) cout << 'c';
      for (int j = 1; j <= i; j++) cout << 'e';
      for (int j = 1; j <= i; j++) cout << 's';
    }
    if (k == 8) {
      for (int j = 1; j <= i - 1; j++) cout << 'c';
      for (int j = 1; j <= i - 1; j++) cout << 'o';
      for (int j = 1; j <= i; j++) cout << 'd';
      for (int j = 1; j <= i; j++) cout << 'e';
      for (int j = 1; j <= i; j++) cout << 'f';
      for (int j = 1; j <= i; j++) cout << 'o';
      for (int j = 1; j <= i; j++) cout << 'r';
      for (int j = 1; j <= i; j++) cout << 'c';
      for (int j = 1; j <= i; j++) cout << 'e';
      for (int j = 1; j <= i; j++) cout << 's';
    }
    if (k == 9) {
      for (int j = 1; j <= i - 1; j++) cout << 'c';
      for (int j = 1; j <= i; j++) cout << 'o';
      for (int j = 1; j <= i; j++) cout << 'd';
      for (int j = 1; j <= i; j++) cout << 'e';
      for (int j = 1; j <= i; j++) cout << 'f';
      for (int j = 1; j <= i; j++) cout << 'o';
      for (int j = 1; j <= i; j++) cout << 'r';
      for (int j = 1; j <= i; j++) cout << 'c';
      for (int j = 1; j <= i; j++) cout << 'e';
      for (int j = 1; j <= i; j++) cout << 's';
    }
    if (k == 10) {
      for (int j = 1; j <= i; j++) cout << 'c';
      for (int j = 1; j <= i; j++) cout << 'o';
      for (int j = 1; j <= i; j++) cout << 'd';
      for (int j = 1; j <= i; j++) cout << 'e';
      for (int j = 1; j <= i; j++) cout << 'f';
      for (int j = 1; j <= i; j++) cout << 'o';
      for (int j = 1; j <= i; j++) cout << 'r';
      for (int j = 1; j <= i; j++) cout << 'c';
      for (int j = 1; j <= i; j++) cout << 'e';
      for (int j = 1; j <= i; j++) cout << 's';
    }
  }
}
