#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
#include <random>
using namespace std;
using namespace __gnu_pbds;
#pragma GCC optimize("O3,Ofast,unroll-loops")
//#pragma GCC target("popcnt")
#define int long long
#define ll long long
#define ld long double
#define endl '\n'
#define pii pair<int,int>
#define debug(...) printf(__VA_ARGS__)
//#define debug(...)
#define trace(x) cout<<#x<<"="<<x<<endl;
//#define trace(x)
#define vi vector<int>
#define popcnt(x) (int)__builtin_popcount(x)
#define vpii vector<pii >
#define vvi vector<vector<int> >
#define umap unordered_map
#define uset unordered_set
#define mk make_pair
#define pb push_back
#define pob pop_back
#define _ <<' '<<
#define all(x) x.begin(),x.end()
#define allr(x) x.rbegin(),x.rend()
#define read(x) for (auto& zu: (x)) cin >> zu;
#define write(x) for (auto& zu: (x))cout << zu<<' '; cout<<endl;
static inline void print(const int &x) {
    if (x > 9)print(x / 10);
    putchar('0' + x % 10);
}

#define F first
#define S second
template<class T> using ordered_set = tree<T, null_type, less<T>, rb_tree_tag, tree_order_statistics_node_update>;
template<class T> using ordered_multiset = tree<T, null_type, less_equal<T>, rb_tree_tag, tree_order_statistics_node_update>;
#define mustawa ios::sync_with_stdio(false);cin.tie(nullptr);
#define mishari main
const int inf=1e9+7;
void fa(bool ok){ cout << (ok ? "YES": "NO") << endl;}
int pw(ll a, ll b, ll mod= 1e9 + 7){
    a %= mod;
    ll res = 1;
    while (b > 0) {
        if (b % 2 == 1) { res = res * a % mod; }
        a = a * a % mod;
        b /= 2;
    }
    return res;
}
inline void usaco(string s) {
    freopen((s + ".in").c_str(), "r", stdin);
    freopen((s + ".out").c_str(), "w", stdout);
}inline void usaco(string s1,string s2) {
    freopen((s1 + ".in").c_str(), "r", stdin);
    freopen((s2 + ".out").c_str(), "w", stdout);
}
int gcd(int a,int b){
    if (b == 0)return a;
    return gcd(b, a % b);
}

int lcm(int a, int b){
    return (a / gcd(a, b)) * b;
}
//long double log(int base,int x){
//    return log2(x)/log(base);
//}
int log(int base,int x){
    return (int)(log2(x)/log(base));
}
int sum(int l,int r){
    if(l>r)swap(l,r);
    int a=((l-1)*(l))/2;
    int b=(r*(r+1))/2;
    return b-a;
}map<char,bool>m;
inline int qry(string& out){
    cout<<out<<endl<<flush;
    string s;
    getline(cin,s);
    if(s=="ACCESS GRANTED")exit(0);
    string g;
    for(char i : s){
        if('0'<=i&&i<='9')g+=i;
    }if(g.empty())return 0;
    return stoll(g);
}
void solve() {
    int len=1;
    string all;
    for(char i='a';i<='z';i++){
        all+=i;
        m[i]=1;
    }for(char i='A';i<='Z';i++){
        all+=i;
        m[i]=1;
    }for(char i='0';i<='9';i++){
        all+=i;
        m[i]=1;
    }
    while(1){
        string out;
        for(int i=0;i<len;i++){
            out+='a';
        }
        int t=qry(out);
        if(t==0)return;
        if(t!=5)break;
        len++;
    }
    string ans;
    for(int i=0;i<len;i++)ans+='a';
    for(int i=0;i<len;i++){
        int t=qry(ans);
        bool b=0;
        for(char j='a'; j <= 'z'&&!b; j++){
            ans[i]=j;
            int t=qry(ans);
            if(t>(i+1)*9+5)b=1;
        }for(char j='A'; j <= 'Z'&&!b; j++){
            ans[i]=j;
            int t=qry(ans);
            if(t>(i+1)*9+5)b=1;
        }for(char j='0'; j <= '9'&&!b; j++){
            ans[i]=j;
            int t=qry(ans);
            if(t>(i+1)*9+5)b=1;
        }
    }

}
signed mishari() {
    mustawa;
    //usaco("nocross");
    //usaco("input","output");
    int tescases = 1;
    //cin>>tescases;
    for (int i = 1; i <= tescases; i++) {
        //cout<<"Case #"<<i<<":"<<' ';
        solve();
    }
}