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

template <typename A, typename B>
string to_string(pair<A, B> p);
 
template <typename A, typename B, typename C>
string to_string(tuple<A, B, C> p);
 
template <typename A, typename B, typename C, typename D>
string to_string(tuple<A, B, C, D> p);
 
string to_string(const string& s) {
  return '"' + s + '"';
}
 
string to_string(const char* s) {
  return to_string((string) s);
}
 
string to_string(bool b) {
  return (b ? "true" : "false");
}
 
string to_string(vector<bool> v) {
  bool first = true;
  string res = "{";
  for (int i = 0; i < static_cast<int>(v.size()); i++) {
    if (!first) {
      res += ", ";
    }
    first = false;
    res += to_string(v[i]);
  }
  res += "}";
  return res;
}
 
template <size_t N>
string to_string(bitset<N> v) {
  string res = "";
  for (size_t i = 0; i < N; i++) {
    res += static_cast<char>('0' + v[i]);
  }
  return res;
}
 
template <typename A>
string to_string(A v) {
  bool first = true;
  string res = "{";
  for (const auto &x : v) {
    if (!first) {
      res += ", ";
    }
    first = false;
    res += to_string(x);
  }
  res += "}";
  return res;
}
 
template <typename A, typename B>
string to_string(pair<A, B> p) {
  return "(" + to_string(p.first) + ", " + to_string(p.second) + ")";
}
 
template <typename A, typename B, typename C>
string to_string(tuple<A, B, C> p) {
  return "(" + to_string(get<0>(p)) + ", " + to_string(get<1>(p)) + ", " + to_string(get<2>(p)) + ")";
}
 
template <typename A, typename B, typename C, typename D>
string to_string(tuple<A, B, C, D> p) {
  return "(" + to_string(get<0>(p)) + ", " + to_string(get<1>(p)) + ", " + to_string(get<2>(p)) + ", " + to_string(get<3>(p)) + ")";
}
 
void debug_out() { cerr << endl; }
 
template <typename Head, typename... Tail>
void debug_out(Head H, Tail... T) {
  cerr << " " << to_string(H);
  debug_out(T...);
}
#ifdef LOCAL
#define debug(...) cerr << "[" << #__VA_ARGS__ << "]:", debug_out(__VA_ARGS__)
#else
#define debug(...) 42
#endif

#define fi first
#define se second
#define pb push_back
#define mod(n,k) ( ( ((n) % (k)) + (k) ) % (k))
#define forn(i,a,b) for(int i = a; i < b; i++)
#define forr(i,a,b) for(int i = a; i >= b; i--)
#define all(x) (x).begin(), (x).end()

typedef long long ll;
typedef long double ld;
typedef pair<int,int> ii;
typedef vector<int> vi;
typedef vector<ii> vii;

int sum(int a, int b,int mod){return (a+b) % mod;}
int sub(int a, int b,int mod){return (a + mod - b) % mod;}
int mul(int a, int b,int mod){return (1ll * a * b) % mod;}
int power(int a,int b,int mod){
	int res = 1;
	while(b){
		if(b&1)res = mul(res,a,mod);
		b >>= 1;
		a = mul(a,a,mod);
	}
	return res;
}


int main(){
	ios_base::sync_with_stdio(0); cin.tie(0);
	ll a,b,c; cin >> a >> b >> c;
	vi res;
	set<int> seen;
	ll act = a%10;
	while(1){
		if(seen.count(act))break;
		res.pb(act);
		seen.insert(act);
		act = mul(act,a,10);
	}
	int pos = power(b,c,res.size());
	pos = sub(pos,1,res.size());
	//debug(res,pos);
	cout << res[pos] << '\n';
	return 0;
}
/*
__builtin_mul_overflow(x,y,&x)
-fsplit-stack
*/

#include <bits/stdc++.h>
using namespace std;
#define rep(i, N) for(int i = 0; i < N; i++)

int main() {
    int N, A[20], min = INT32_MAX;
    cin >> N;
    rep(i, N) cin >> A[i];

    for (int bit = 0; bit < (1 << (N - 1)); bit++) {
        int OR = 0, XOR = 0;
        for (int i = 0; i < N - 1; i++) {
            OR = OR | A[i];
            if (bit & (1 << i)) {
                XOR = XOR ^ OR;
                OR = 0;
            }
        }
        OR = OR | A[N - 1];
        XOR = XOR ^ OR;

        if (min > XOR) min = XOR;
    }
    cout << min << endl;
}