#include <bits/stdc++.h>
#include <atcoder/all>
using namespace std;
using namespace atcoder;
#define rep(i, n) for(int i=0;i<(n);++i)
#define rep1(i, n) for(int i=1;i<=(n);i++)
#define ll long long
using mint = modint998244353;
using P = pair<ll,ll>;
using lb = long double;
using T = tuple<ll, ll, ll>;
#ifdef LOCAL
#  include <debug_print.hpp>
#  define dbg(...) debug_print::multi_print(#__VA_ARGS__, __VA_ARGS__)
#else
#  define dbg(...) (static_cast<void>(0))
#endif

int out(string t) {
    cout << "? " << t << endl;
    int cnt;
    cin >> cnt;
    return cnt;
}   

int main()
{
    int n;
    cin >> n;
    string s;
    rep(i,n) s += 'z';
    rep(i,n) {
        vector<int> t(26);
        set<int> st;
        rep(j,25) {
            s[i] = 'a' + j;
            t[j] = out(s);
            st.insert(t[j]);
        }
        if(st.size()==1) s[i] = 'z';
        else{
            int c = *st.rbegin();
            rep(j,25) {
                if(c==t[j]) s[i] = 'a'+j;
            }
        }
    }
    cout<< "! " << s << endl;
    return 0;
}