codeforces - coforces subsequence

#include<bits/stdc++.h>
using namespace std;
#define ll long long
#define fast()(ios_base::sync_with_stdio(0),cin.tie(NULL));
int main()
{
    fast()
    ll n;
    cin>>n;
    string s="codeforces";
    ll ara[10],sum = 1;
    for(ll i=0 ;i<10;i++)ara[i]=1;
    for(ll i=0; i<10 && sum<n;i++)
    {
        sum/=ara[i];
        ara[i]++;
        sum*=ara[i];
        if(i==9)i=-1;
    }
    for(ll i=0;i<10;i++)
    {
        for(ll j=1;j<=ara[i];j++)cout<<s[i];
    }
    cout<<"\n";

}