#include <bits/stdc++.h>

using namespace std;
using ll = long long;
using ld = long double;
using Vec = vector<int>;
using Graph = vector<vector<int>>;

int MOD=1000000007;
ll ll_max=9223372036854775807;
	      

bool IsPrime(int num)
{
    if (num < 2) return false;
    else if (num == 2) return true;
    else if (num % 2 == 0) return false; 
    double sqrtNum = sqrt(num);
    for (int i = 3; i <= sqrtNum; i += 2)
    {
        if (num % i == 0)
        {
            // 素数ではない
            return false;
        }
    }

    // 素数である
    return true;
}


int Gcd(int x,int y)              //最大公約数
{
  int large = max(x,y);
  int small = min(x,y);

  while(small!=0){
      int amari =large%small;

      large = small;

      small = amari;  
  }
  return large;
}

   vector<bool> seen;  
void dfs(const Graph &G, int v)   //深さ優先探索
{   seen[v] = true;
     for (auto next_v : G[v]) { 
      if (seen[next_v]) continue;
     dfs(G, next_v); // 再帰的に探索
    }
}

ll combi(ll n, ll r){
  if (r == 0) {
      return 1;
  }
  return (n - r + 1) * combi(n, r - 1) / r;
}



//メイン関数--------------------------------------------



int main(){

int n;
cin>>n;
vector<string> v(n);
for(int i=0;i<n;i++){

string s;
cin>>s;
    if(s[0]=='!'){
        s.erase(0,1);
        s.push_back('A');
    }
    v[i]=s;
}

sort(v.begin(),v.end());
bool x=true;
for(int i=0;i<n-1;i++){
    if(v[i]+'A'==v[i+1]){
        cout<<v[i]<<endl;
        x=false;
        break;
    }
}
if(x) cout<<"satisfiable"<<endl;








}

/*ver 7*/
#include <bits/stdc++.h>
using namespace std;
void init() {cin.tie(0);ios::sync_with_stdio(false);cout << fixed << setprecision(15);}
using ll = long long;
using ld = long double;
using vl = vector<ll>;
using vd = vector<ld>;
using vs = vector<string>;
using vb = vector<bool>;
using vvl = vector<vector<ll>>;
using vvd = vector<vector<ld>>;
using vvs = vector<vector<string>>;
using vvb = vector<vector<bool>>;
using pll = pair<ll,ll>;
using mll = map<ll,ll>;
template<class T> using V = vector<T>;
template<class T> using VV = vector<vector<T>>;
#define each(x,v) for(auto& x : v)
#define reps(i,a,b) for(ll i=(ll)a;i<(ll)b;i++)
#define rep(i,n) for(ll i=0;i<(ll)n;i++)
#define pb push_back
#define eb emplace_back
#define fi first
#define se second
#define mp make_pair
const ll INF = 1LL << 60;
#define CLR(mat,f) memset(mat, f, sizeof(mat))
#define IN(a, b, x) (a<=x&&x<=b)
#define UNIQUE(v) v.erase( unique(v.begin(), v.end()), v.end() ) //被り削除
#define debug cout << "line : " << __LINE__ << " debug" << endl;
#define ini(...) int __VA_ARGS__; in(__VA_ARGS__)
#define inl(...) long long __VA_ARGS__; in(__VA_ARGS__)
#define ind(...) long double __VA_ARGS__; in(__VA_ARGS__)
#define ins(...) string __VA_ARGS__; in(__VA_ARGS__)
#define inc(...) char __VA_ARGS__; in(__VA_ARGS__)
void in(){}
template <typename T,class... U> void in(T &t,U &...u){ cin >> t; in(u...);}
template <typename T> void in1(T &s) {rep(i,s.size()){in(s[i]);}}
template <typename T> void in2(T &s,T &t) {rep(i,s.size()){in(s[i],t[i]);}}
template <typename T> void in3(T &s,T &t,T &u) {rep(i,s.size()){in(s[i],t[i],u[i]);}}
template <typename T> void in4(T &s,T &t,T &u,T &v) {rep(i,s.size()){in(s[i],t[i],u[i],v[i]);}}
template <typename T> void in5(T &s,T &t,T &u,T &v,T &w) {rep(i,s.size()){in(s[i],t[i],u[i],v[i],w[i]);}}
void out(){cout << endl;}
template <typename T,class... U> void out(const T &t,const U &...u){cout << t; if(sizeof...(u)) cout << " "; out(u...);}
void die(){cout << endl;exit(0);}
template <typename T,class... U> void die(const T &t,const U &...u){cout << t; if(sizeof...(u)) cout << " "; die(u...);}
template <typename T> void outv(T s) {rep(i,s.size()){if(i!=0)cout<<" ";cout<<s[i];}cout<<endl;}
template <typename T> void out1(T s) {rep(i,s.size()){out(s[i]);}}
template <typename T> void out2(T s,T t) {rep(i,s.size()){out(s[i],t[i]);}}
template <typename T> void out3(T s,T t,T u) {rep(i,s.size()){out(s[i],t[i],u[i]);}}
template <typename T> void out4(T s,T t,T u,T v) {rep(i,s.size()){out(s[i],t[i],u[i],v[i]);}}
template <typename T> void out5(T s,T t,T u,T v,T w) {rep(i,s.size()){out(s[i],t[i],u[i],v[i],w[i]);}}
#define all(v) (v).begin(),(v).end()
#define rall(v) (v).rbegin(),(v).rend()
template <typename T> T allSum(vector<T> a){T ans=T();each(it,a)ans+=it;return ans;}
ll ceilDiv(ll a,ll b) {return (a+b-1)/b;}
ld dist(pair<ld,ld> a, pair<ld,ld> b){return sqrt(abs(a.fi-b.fi)*abs(a.fi-b.fi)+abs(a.se-b.se)*abs(a.se-b.se));} // ２点間の距離 
ll gcd(ll a, ll b) { return b != 0 ? gcd(b, a % b) : a; }
ll lcm(ll a,ll b){ return a / gcd(a,b) * b;}
template <class A, class B> inline bool chmax(A &a, const B &b) { return b > a && (a = b, true); }
template <class A, class B> inline bool chmin(A &a, const B &b) { return b < a && (a = b, true); }
#define YES(n) ((n) ? "YES" : "NO"  )
#define Yes(n) ((n) ? "Yes" : "No"  )
#define yes(n) ((n) ? "yes" : "no"  )

int main(){
	init();
    set<string> st;
    inl(n);
    rep(i,n){
        ins(s);
        st.insert(s);
    }
    for(auto &x:st){
        if(x[0]!='!')continue;
        if(st.count(x.substr(1))==1)die(x.substr(1));
    }
    out("satisfiable");
	return 0;
}