#include #define M_PI 3.14159265358979323846 using namespace std; //conversion //------------------------------------------ inline int toInt(string s) { int v; istringstream sin(s); sin >> v; return v; } template inline string toString(T x) { ostringstream sout; sout << x; return sout.str(); } inline int readInt() { int x; scanf("%d", &x); return x; } //typedef //------------------------------------------ typedef vector VI; typedef vector VVI; typedef vector VS; typedef pair PII; typedef pair TIII; typedef long long LL; typedef unsigned long long ULL; typedef vector VLL; typedef vector VVLL; //container util //------------------------------------------ #define ALL(a) (a).begin(),(a).end() #define RALL(a) (a).rbegin(), (a).rend() #define PB push_back #define MP make_pair #define SZ(a) int((a).size()) #define SQ(a) ((a)*(a)) #define EACH(i,c) for(typeof((c).begin()) i=(c).begin(); i!=(c).end(); ++i) #define EXIST(s,e) ((s).find(e)!=(s).end()) #define SORT(c) sort((c).begin(),(c).end()) //repetition //------------------------------------------ #define FOR(i,s,n) for(int i=s;i<(int)n;++i) #define REP(i,n) FOR(i,0,n) #define MOD 1000000007 #define rep(i, a, b) for(int i = a; i < (b); ++i) #define trav(a, x) for(auto& a : x) #define all(x) x.begin(), x.end() #define sz(x) (int)(x).size() typedef long long ll; typedef pair pii; typedef vector vi; const double EPS = 1E-8; #define chmin(x,y) x=min(x,y) #define chmax(x,y) x=max(x,y) const int INF = 100000000; struct Edge { int to, from; ll cost; Edge(int from, int to, ll cost): from(from), to(to), cost(cost) {} }; struct UnionFind { vector data; UnionFind(int size) : data(size, -1) { } bool unionSet(int x, int y) { x = root(x); y = root(y); if (x != y) { if (data[y] < data[x]) swap(x, y); data[x] += data[y]; data[y] = x; } return x != y; } bool findSet(int x, int y) { return root(x) == root(y); } int root(int x) { return data[x] < 0 ? x : data[x] = root(data[x]); } int size(int x) { return -data[root(x)]; } }; typedef vector> AdjList; AdjList graph; bool comp(const Edge& e1, const Edge& e2) { return e1.cost < e2.cost; } vector split_naive(const string &s, char delim) { vector elems; string item; for (char ch: s) { if (ch == delim) { if (!item.empty()) elems.push_back(atoi(item.c_str())); item.clear(); } else { item += ch; } } if (!item.empty()) elems.push_back(atoi(item.c_str())); return elems; } ll mod_pow(ll x, ll n, ll mod){ ll res = 1; bool c = false; while(n){ if(n&1) res = res * x; if(res > mod){ c = true; res %= mod; } x = x * x %mod; n >>= 1; } if(c) return mod; return res; } #define SIEVE_SIZE 10000+10 bool sieve[SIEVE_SIZE]; void make_sieve(){ for(int i=0; i vector gauss_jordan(const vector>& A, const vector& b){ int n = A.size(); vector> B(n, vector(n+1)); for(int i=0; i abs(B[pivot][i])) pivot = j; } swap(B[i], B[pivot]); if(abs(B[i][i]) < EPS) return vector(); //解なし for(int j=i+1; j<=n; ++j) B[i][j] /= B[i][i]; for(int j=0; j x(n); for(int i=0; i vec; typedef vector mat; mat mul(mat &A, mat &B) { mat C(A.size(), vec((int)B[0].size())); for(int i=0; i 0) { if(n & 1) B = mul(B, A); A = mul(A, A); n >>= 1; } return B; } int nxt[26]; bool used[26]; int main() { cin.tie(0); ios::sync_with_stdio(false); //cout << fixed << setprecision(10); int n; cin >> n; REP(i,26) nxt[i] = -1; string A[n]; REP(i,n) { cin >> A[i]; REP(j, A[i].size()-1){ nxt[A[i][j]-'A'] = A[i][j+1] - 'A'; } REP(j,A[i].size()) used[A[i][j]-'A'] = true; } int m; cin >> m; string B[m]; REP(i,m) { cin >> B[i]; REP(j, B[i].size()-1){ nxt[B[i][j]-'A'] = B[i][j+1] - 'A'; } REP(j,B[i].size()) used[B[i][j]-'A'] = true; } int sz=0; for(int i=0; i<26; ++i)if(used[i]) sz++; for(int i=0; i<26; ++i){ string s; if(!used[i]) continue; int pos = i; while(pos != -1){ s += (char)(pos + 'A'); pos = nxt[pos]; } if(s.size() == sz){ cout << s << endl; return 0; } } cout << -1 << endl; return 0; }