/*Bismillahi-r-Rahmani-r-Rahim*/
#include<bits/stdc++.h>
using namespace std;
#define  ll         long long
#define  pi         acos(-1.0)
#define  mod        1000000007
#define  yes        cout<<"YES"<<endl
#define  no         cout<<"NO"<<endl
#define  vi         vector<int>
#define  vl         vector<ll int>
#define  pb         push_back
#define  test       cin>>t;while(t--)
#define  lcm(a,b)   a*b/__gcd(a,b)
#define  sd         second
#define  ft         first

int main()
{
     ios_base::sync_with_stdio(false);cin.tie(NULL);
     ll int i,n,t,j=0,p,x,a=0,b,l=0,r=0,y,k,c,sum=0,m,d,cnts=0;
     cin>>n;
     map<string,int>mp;
    // map<string,int>:: iterator it;

     string sm,sp;
     for(i=0;i<n;i++){
        cin>>sm;
        mp[sm]++;
     }
     i=0;
     string s[mp.size()];
     for(auto it : mp){
       sp=it.ft;
       if(sp[0]=='!'){
        sp=sp.substr(1,sp.size()-1);
       }

       s[i++]=sp;

     }
     l=0;
     sort(s,s+mp.size());
     for(i=0;i<mp.size()-1;i++){
        if(s[i]==s[i+1]){
            l=1;sm=s[i];break;
        }
     }
     if(l==0){
        cout<<"satisfiable"<<endl;
     }
     else{
        cout<<sm<<endl;
     }











}

#define pb push_back
#define mp make_pair
#define fi first
#define se second 
#define all(...) begin(__VA_ARGS__) , end(__VA_ARGS__)
#define boost {ios_base::sync_with_stdio(false); cin.tie(); cout.tie();}

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

typedef long long ll;
typedef unsigned long long ull;
typedef long double ld;
typedef vector <int> vi;
typedef pair<int,int> PII;
typedef pair<ll,ll> PLL;
constexpr ll nax = 2e5+6969, INF = 2e9+6969;

int n;
set <string> a,b;

int main()
{
	cin >> n;
	for(int i=0;i<n;i++)
	{
		string tmp;
		cin >> tmp;
		if(tmp[0] == '!') a.insert(tmp);
		else b.insert(tmp);
	}
	string ans = "satisfiable";
	for(auto e: b)
	{
		string tmp = "!" + e;
		if(a.find(tmp) != a.end()) ans = e;
	}
	cout << ans << "\n";
	return 0;
}
