#include <bits/stdc++.h>
using namespace std;

//----------------------------------------------------------------------------------
#define pb insert//                                                                 |
#define eb emplace_back//                                                           |
#define ff first//                                                                  |
#define ss second//                                                                 |
typedef long long int ll;//                                                         |
typedef long double ld;//                                                           |
#define all(a) a.begin(), a.end()//                                                 |
#define show(x) cerr << #x << " is " << x << "\n"//                                 |
#define show2(x, y) cerr << #x << " " << #y << " " << x << " " << y << "\n"//       |
typedef vector<ll> vl;//                                                            |
typedef vector<vl> vvl;//                                                           |
typedef pair<ll, ll> pp;//                                                          |
typedef vector<pp> vp;//                                                            |
typedef map<pp, ll> ipi;//                                                          |
typedef map<pp, char> ipc;//                                                        |
typedef map<ll, ll> ii;//                                                           |
typedef set<ll> sl;//                                                               |
typedef multiset<ll> msl;//                                                         |
typedef map<char, ll> ci;//                                                         |
typedef set<pair<ll, ll>> sp;//                                                     |
const ll mod = 1e9 + 7;//                                                           |
const ll N = 2e4 + 1;//                                                             |
//----------------------------------------------------------------------------------

ll fast_expo(ll x, ll y){
    
    ll res=1;
    while(y>0){
        if(y&1){
            res*=x;
        }
        x*=x;
        y>>=1;
    }
    return res;
}


//main func
int main()
{
	ios_base::sync_with_stdio(false);
	cin.tie(0);
	cout.tie(0);
    
    ll t;cin>>t;
    string s="abcdefghijklmnopqrstuvwxyz";
    string str="";
    map<ll,string> m;
    m[0]="0";
    m[1]="1";
    m[2]="2";
    m[3]="3";
    m[4]="4";
    m[5]="5";
    m[6]="6";
    m[7]="7";
    m[8]="8";
    m[9]="9";
    m[10]="10";
    m[11]="11";
    m[12]="12";
    m[13]="13";
    m[14]="14";
    m[15]="15";
    m[16]="16";
    m[17]="17";
    m[18]="18";
    m[19]="19";
    m[20]="20";
    m[21]="21";
    m[22]="22";
    m[23]="23";
    m[24]="24";
    m[25]="25";
    map<string ,ll> m2;
    for(auto i:m){
        m2[i.ss]=i.ff;
    }
    vector<string> v;
    int f=0;
    while(t>0){
        t--;
        v.eb(m[t%26]);
        t/=26;
    }
    string ans="";
    reverse(all(v));
    for(auto i:v) 
    {   if(f)
        ans+=s[m2[i]];
        else ans+=s[m2[i]];
    }
    cout<<ans<<"\n";
    
	return 0;
}

Measured memory_bytes: 3588