#pragma GCC optimize("Ofast")
#pragma GCC optimize("unroll-loops")
//#pragma GCC target("sse,sse2,sse3,ssse3,sse4,popcnt,abm,mmx,avx,tune=native")
#ifdef local
#include <C++/core/io/debug_print.hpp>
#else
#define dump(...) void(0);
#endif

#include <iostream>
#include <ranges>
#include <cassert>
#include <unordered_set>
namespace man {

}
int main() {
    std::cin.tie(nullptr) -> sync_with_stdio(false);
    using namespace std::views;
    char a;
    std::cin >> a;
    std::unordered_set<std::string> t;
    while(true) {
        std::string s;
        s += a;
        for(const auto c: iota('a', 'z' + 1)) {
            s += c;
            if(t.contains(s)) {
                s.pop_back();
            } else {
                std::cout << "? " << s << std::endl;
                t.emplace(s);
                break;
            }
        }
        if(std::ssize(t) == 51) {
            break;
        }
        char dummy;
        std::cin >> dummy >> s;
        assert(std::ssize(s) == 2);
        if(t.contains(s)) {
            break;
        }
        t.emplace(s);
        a = s.back();
    }
    std::cout << "! WIN" << std::endl;
}