//#pragma GCC optimize("Ofast")

#include <bits/stdc++.h>

using namespace std;

void debug_out() { cerr << endl; }

template<typename Head, typename... Tail>
void debug_out(Head H, Tail... T) {
    cerr << "[" << H << "]";
    debug_out(T...);
}

#ifdef dddxxz
#define debug(...) cerr << "[" << #__VA_ARGS__ << "]:", debug_out(__VA_ARGS__)
#else
#define debug(...) 42
#endif

#define SZ(s) ((int)s.size())

clock_t startTime;

double getCurrentTime() {
    return (double) (clock() - startTime) / CLOCKS_PER_SEC;
}

typedef long long ll;
//mt19937 rng(chrono::high_resolution_clock::now().time_since_epoch().count());
const double eps = 0.00001;
const int MOD = 1e9 + 7;
const int INF = 1000000101;
const long long LLINF = 1223372000000000555;
const int N = 1e6 + 4e4;
const int M = 1234;
const int LOG = 18;

void solve(int TC) {
    int n;
    cin >> n;

    set<string> st;
    for (int i = 1; i <= n; i++){
        string s;
        cin >> s;
        string t = s;
        if (*t.begin() == '!') t.erase(t.begin()); else
            t = "!" + t;
        if (st.count(t)){
            cout << (*s.begin() != '!' ? s : t) << endl;
            return;
        }
        st.insert(s);
    }

    cout << "satisfiable";

}

int main() {
    startTime = clock();
    ios_base::sync_with_stdio(false);

    bool llololcal = false;
#ifdef dddxxz
    freopen("input.txt", "r", stdin);
    freopen("output.txt", "w", stdout);
    llololcal = true;
#endif

    int TC = 1;
    //cin >> TC;

    for (int test = 1; test <= TC; test++) {
        debug(test);
        solve(test);
    }

    if (llololcal) cerr << endl << "Time: " << getCurrentTime() * 1000 << " ms" << endl;

    return 0;
}
#include <bits/stdc++.h>
#define rep(i,n) for (int i = 0; i < (n); ++i)
using namespace std;
using ll = long long;
using P = pair<int,int>;

ll INF = 1e18;

 
int main() {
  
  int n;
  cin >> n;
  vector<string> a;
  set<string> b;
  int count = 0;
  rep(i,n){
    string s;
    cin >> s;
    if(s[0] == '!'){
      b.insert(s);
    }
    else{
      a.push_back(s);
      count++;
    }
  }
  rep(i,count){
    if(b.count('!'+a[i])){
      cout << a[i] << endl;
      return 0;
    }
  }
  cout << "satisfiable" << endl;
  
  
  return 0;
}