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

int main(){
    ios::sync_with_stdio(false);
    cin.tie(0);
    constexpr int r = 19;
    array<int, r> tmp;
    auto ask1 = [&](char c){
        for(int i = 0; i < r; i++){
            cout << "? " << c << endl;
            cin >> tmp[i];
        }
        sort(tmp.begin(), tmp.end());
        pair<int,int> mx;
        for(int i = 0; i < r; ){
            int p = i;
            while(i < r && tmp[i] == tmp[p]) i++;
            mx = max(mx, make_pair(i - p, tmp[p]));
        }
        return mx.second;
    };
    auto ask2 = [&](char c0, char c1, char c2){
        int res;
        cout << "+ " << c0 << " " << c1 << " " << c2 << endl;
        cin >> res;
        assert(res == 0);
    };
    int x = ask1('A');
    int y = ask1('B');
    int v = 0;
    char c0 = 'A', c1 = 'B';
    while(y){
        if(y & 1){
            v += x;
            do{
                ask2(c0, c0, 'C');
            }while(ask1('C') != v);
        }
        do{
            ask2(c0, c0, c1);
        }while(ask1('C') != 2 * x);
        x += x;
        swap(c0, c1);
    }
    cout << "! C" << endl; 
}