#include<iostream>
#include<string>
#include<algorithm>
#include<cstdio>
#include<cstring>
#include<cmath>
#include<map>
#include <queue>
#include<sstream>
#include <stack>
#include <set>
#include <bitset>
#include<vector>
#define FAST ios::sync_with_stdio(false)
#define abs(a) ((a)>=0?(a):-(a))
#define sz(x) ((int)(x).size())
#define all(x) (x).begin(),(x).end()
#define mem(a,b) memset(a,b,sizeof(a))
#define max(a,b) ((a)>(b)?(a):(b))
#define min(a,b) ((a)<(b)?(a):(b))
#define rep(i,a,n) for(int i=a;i<=n;++i)
#define per(i,n,a) for(int i=n;i>=a;--i)
#define endl '\n'
#define pb push_back
#define mp make_pair
#define fi first
#define se second
using namespace std;
typedef long long ll;
typedef pair<ll,ll> PII;
const int maxn = 1e5+200;
const int inf=0x3f3f3f3f;
const double eps = 1e-7;
const double pi=acos(-1.0);
const int mod = 1e9+7;
inline int lowbit(int x){return x&(-x);}
ll gcd(ll a,ll b){return b?gcd(b,a%b):a;}
void ex_gcd(ll a,ll b,ll &d,ll &x,ll &y){if(!b){d=a,x=1,y=0;}else{ex_gcd(b,a%b,d,y,x);y-=x*(a/b);}}//x=(x%(b/d)+(b/d))%(b/d);
inline ll qpow(ll a,ll b,ll MOD=mod){ll res=1;a%=MOD;while(b>0){if(b&1)res=res*a%MOD;a=a*a%MOD;b>>=1;}return res;}
inline ll inv(ll x,ll p){return qpow(x,p-2,p);}
inline ll Jos(ll n,ll k,ll s=1){ll res=0;rep(i,1,n+1) res=(res+k)%i;return (res+s)%n;}
inline ll read(){ ll f = 1; ll x = 0;char ch = getchar();while(ch>'9'||ch<'0') {if(ch=='-') f=-1; ch = getchar();}while(ch>='0'&&ch<='9') x = (x<<3) + (x<<1) + ch - '0',  ch = getchar();return x*f; }
int dir[4][2] = { {1,0}, {-1,0},{0,1},{0,-1} };

int main()
{
    ll n  = read();
    map<string,int> Map;
    vector<string> item;
    rep(i,1,n)
    {
        string s;
        cin>>s;
        Map[s] = 1;
        item.pb(s);
    }
    int flag = 0;
    rep(i,1,n)
    {
        if(item[i-1][0]=='!')
        {
            string t(item[i-1],1,item[i-1].size());
            if(Map[t])
            {
                cout<<t<<endl;
                flag = 1;
                break;
            }
        }
    }
    if(!flag) cout<<"satisfiable"<<endl;
    return 0;
}

#include<bits/stdc++.h>
#define ll long long 
using namespace std;
void solve(){
    long long n,m,tot=0,cnt=0;
    string s,k="";
    bool ok=1;
    cin>>n;
    map<string,int>mp;
    for(int i=0;i<n;i++){
        cin>>s;
        if(s[0]=='!'){
           mp[s]++;
           s=s.substr(1);
           if(mp.find(s)!=mp.end()) k=s;
        }
        else{
           mp[s]++;
           s="!"+s;
           if(mp.find(s)!=mp.end()) k=s.substr(1);
        }
    }
    if(k=="") cout<<"satisfiable"<<endl;
    else cout<<k<<endl;
}
int main()
 {
    #ifndef ONLINE_JUDGE
        freopen("input.txt", "r", stdin);
        freopen("bhar.txt", "w", stdout);
    #endif
    long long q(1);//cin>>q; 
    while(q--){
        solve();
    }
    return 0;
}