#include <bits/stdc++.h>
#define boAshraf ios_base::sync_with_stdio(false); cin.tie(NULL);
#define ll long long
#define sz(s) (int)(s).size()
#define all(s) (s).begin(),(s).end()
using namespace std;
void File();
void sol();
const int N=20;
string ans[N]{};
struct word{
    int len,freq,k,subseq,sbstr;
    char curr;
    vector<int>fs;
    word(){
        k=0, subseq=1, len=0, freq=0, curr='a';
        sbstr=0;
        fs=vector<int>{0};
    }
    bool add(int nw){
        if((nw && curr=='z') || (nw && len==0))return false;
        len++;
        if(nw){
            freq=1;
            curr++;
            subseq*=2;
            sbstr+=len;
            fs.emplace_back(1);
        }
        else {
            subseq/=(freq + 1);
            freq++;
            subseq*=(freq + 1);
            sbstr++;
            fs.back()++;
        }
        k= subseq - sbstr;
        if(k>=N)return false;
        return true;
    }
    string get_str(){
        string st="a";
//        char s='a';
//        for(auto it:fs)st+=string(it,s++);
        return st;
    }
};
void pre(){
    queue<word>q;
    word st;
    q.emplace(st);
    while(!q.empty()){
        auto curr=q.front();
        q.pop();
        if(curr.k>=N)break;
        word w1=curr,w2=curr;
        if(w1.add(0)) {
            if (ans[w1.k].empty()) {
                ans[w1.k] = w1.get_str();
            }
            q.emplace(w1);
        }
        if(w2.add(1)){
            if(ans[w2.k].empty()) {
                ans[w2.k] = w2.get_str();
            }
            q.emplace(w2);
        }
    }
}
int main() {
    boAshraf
    File();
    int t = 1;
    cin >> t;
    pre();
    while (t--) {
        sol();
    }
    return 0;
}

void sol() {
    int s;
    cin>>s;
    cout<<ans[s]<<'\n';
}
ccccc
void File() {
#ifndef ONLINE_JUDGE
    freopen("input.txt", "r", stdin);
    freopen("output.txt", "w", stdout);
#endif
}