#include <bits/stdc++.h>
#define fi first
#define se second
#define rep(i,n) for(int i = 0; i < (n); ++i)
#define rrep(i,n) for(int i = 1; i <= (n); ++i)
#define drep(i,n) for(int i = (n)-1; i >= 0; --i)
#define srep(i,s,t) for (int i = s; i < t; ++i)
#define rng(a) a.begin(),a.end()
#define rrng(a) a.rbegin(),a.rend()
#define maxs(x,y) (x = max(x,y))
#define mins(x,y) (x = min(x,y))
#define isin(x,l,r) ((l) <= (x) && (x) < (r))
#define pb push_back
#define eb emplace_back
#define sz(x) (int)(x).size()
#define pcnt __builtin_popcountll
#define uni(x) x.erase(unique(rng(x)),x.end())
#define snuke srand((unsigned)clock()+(unsigned)time(NULL));
#define show(x) cout<<#x<<" = "<<x<<endl;
#define PQ(T) priority_queue<T,v(T),greater<T> >
#define bn(x) ((1<<x)-1)
#define dup(x,y) (((x)+(y)-1)/(y))
#define newline puts("")
#define v(T) vector<T>
#define vv(T) v(v(T))
using namespace std;
typedef long long int ll;
typedef unsigned uint;
typedef unsigned long long ull;
typedef pair<int,int> P;
typedef tuple<int,int,int> T;
typedef vector<int> vi;
typedef vector<vi> vvi;
typedef vector<ll> vl;
typedef vector<P> vp;
typedef vector<T> vt;
inline int getInt() { int x; scanf("%d",&x); return x;}
template<typename T>inline istream& operator>>(istream&i,v(T)&v)
{rep(j,sz(v))i>>v[j];return i;}
template<typename T>string join(const v(T)&v)
{stringstream s;rep(i,sz(v))s<<' '<<v[i];return s.str().substr(1);}
template<typename T>inline ostream& operator<<(ostream&o,const v(T)&v)
{if(sz(v))o<<join(v);return o;}
template<typename T1,typename T2>inline istream& operator>>(istream&i,pair<T1,T2>&v)
{return i>>v.fi>>v.se;}
template<typename T1,typename T2>inline ostream& operator<<(ostream&o,const pair<T1,T2>&v)
{return o<<v.fi<<","<<v.se;}
template<typename T>inline ll suma(const v(T)& a) { ll res(0); for (auto&& x : a) res += x; return res;}
const double eps = 1e-10;
const ll LINF = 1001002003004005006ll;
const int INF = 1001001001;
#define dame { puts("-1"); return 0;}
#define yn {puts("Yes");}else{puts("No");}
const int MX = 200005;

const int L = 128;
const int C = 62;
string cs;

string ans = "AtCoderI5Great";
// string ans = "abbaba";

using SP = pair<int,string>;

//*
int f(const string& s) {
  cout<<"?"<<" "<<s<<endl;
  int res;
  cin>>res;
  return res;
}
/*/
int dp[L+5][L+5];
int qcnt;
int f(const string& s) {
  ++qcnt;
  int n = sz(ans);
  int m = sz(s);
  rep(i,n+1)rep(j,m+1) dp[i][j] = INF;
  dp[0][0] = 0;
  rep(i,n+1)rep(j,m+1) {
    mins(dp[i][j+1], dp[i][j]+1);
    mins(dp[i+1][j], dp[i][j]+1);
    if (i < n && j < m) {
      if (ans[i] == s[j]) mins(dp[i+1][j+1], dp[i][j]);
      else mins(dp[i+1][j+1], dp[i][j]+1);
    }
  }
  cout<<s<<" "<<dp[n][m]<<endl;
  return dp[n][m];
}
//*/

int main() {
  // snuke;
  rep(i,26) cs += 'a'+i;
  rep(i,26) cs += 'A'+i;
  rep(i,10) cs += '0'+i;
  // while (sz(ans) < L) ans += cs[rand()%C];
  int n = 0;
  {
    int l = 0, r = L;
    while (l+1<r) {
      int c = (l+r)>>1;
      int dif = f(string(c+1,cs[0])) - f(string(c,cs[0]));
      if (dif == 1) r = c; else l = c;
    }
    n = r;
  }
  // cout<<n<<endl;
  PQ(SP) q;
  rep(i,C) {
    int cnt = n-f(string(n,cs[i]));
    q.emplace(cnt,string(cnt,cs[i]));
  }
  while (sz(q) > 1) {
    string s = q.top().se; q.pop();
    string t = q.top().se; q.pop();
    int pre = n-sz(s);
    int i = 0, j = 0;
    while (i < sz(s) && j < sz(t)) {
      s.insert(s.begin()+i, t[j]);
      int now = f(s);
      if (now < pre) {
        ++j;
        pre = now;
      } else {
        s.erase(s.begin()+i);
      }
      ++i;
    }
    while (j < sz(t)) s += t[j], ++j;
    q.emplace(sz(s),s);
  }
  // cout<<qcnt<<endl;
  cout<<"!"<<" "<<q.top().se<<endl;
  return 0;
}






















Measured memory_bytes: 3800