#pragma GCC optimize("Ofast")
#pragma GCC optimize("unroll-loops")
#pragma GCC target("sse,sse2,sse3,ssse3,sse4,popcnt,abm,mmx,avx,tune=native")
#include <bits/stdc++.h>
using namespace std;
using ll = long long;
using ull = unsigned long long;
using db = double;
using ld = long double;
template <typename T> using V = vector<T>;
template <typename T> using VV = vector<vector<T>>;
template <typename T> using PQ = priority_queue<T>;
#define fs first
#define sc second
#define pb push_back
#define mp make_pair
#define mt make_tuple
#define eb emplace_back
#define lb(c, x) distance((c).begin(), lower_bound(all(c), (x)))
#define ub(c, x) distance((c).begin(), upper_bound(all(c), (x)))
#define all(v) (v).begin(), (v).end()
#define siz(v) (ll)(v).size()
#define rep(i, a, n) for(ll i = a; i < (ll)(n); ++i)
#define repr(i, a, n) for(ll i = n - 1; (ll)a <= i; --i)
#define ENDL '\n'
typedef pair<int, int> Pi;
typedef pair<ll, ll> PL;
constexpr ll mod = 1000000007;  // 998244353;
constexpr ll INF = 1000000099;
constexpr ll LINF = (ll)(1e18 + 99)*8;
const ld PI = acos((ld)-1);
constexpr ll dx[4] = {-1, 0, 1, 0}, dy[4] = {0, 1, 0, -1};
template <typename T, typename U> inline bool chmin(T& t, const U& u) {
  if(t > u) {
    t = u;
    return 1;
  }
  return 0;
}
template <typename T, typename U> inline bool chmax(T& t, const U& u) {
  if(t < u) {
    t = u;
    return 1;
  }
  return 0;
}
template <typename T> inline T gcd(T a, T b) { return b ? gcd(b, a % b) : a; }
inline void Yes() { cout << "Yes" << ENDL; }
inline void No() { cout << "No" << ENDL; }
inline void YES() { cout << "YES" << ENDL; }
inline void NO() { cout << "NO" << ENDL; }

template <typename T, typename Y> inline T mpow(T a, Y n) {
  T res = 1;
  for(; n; n >>= 1) {
    if(n & 1) res = res * a;
    a = a * a;
  }
  return res;
}

template <typename T> vector<T> finddivisor(T x) {  //整数xの約数(xを含む)
  vector<T> divisor;
  for(T i = 1; (i * i) <= x; i++) {
    if(x % i == 0) {
      divisor.push_back(i);
      if(i * i != x) { divisor.push_back(x / i); }
    }
  }
  sort(divisor.begin(), divisor.end());
  return divisor;
}

template <typename T> V<T> prefix_sum(const V<T>& v) {
  int n = v.size();
  V<T> ret(n + 1);
  rep(i, 0, n) ret[i + 1] = ret[i] + v[i];
  return ret;
}

template <typename T> T rand(T l, T r) {
  static random_device rd;
  static mt19937 g(rd());
  return uniform_int_distribution<T>(l, r)(g);
}

template <typename T> istream& operator>>(istream& is, vector<T>& vec) {
  for(auto&& x : vec) is >> x;
  return is;
}

template <typename T, typename Y>
ostream& operator<<(ostream& os, const pair<T, Y>& p) {
  return os << "{" << p.fs << "," << p.sc << "}";
}

template <typename T> ostream& operator<<(ostream& os, const V<T>& v) {
  os << "{";
  for(auto e : v) os << e << ",";
  return os << "}";
}

template <typename... Args> void debug(Args&... args) {
  for(auto const& x : {args...}) { cerr << x << ' '; }
  cerr << ENDL;
}

template <typename T> T extgcd(T a, T b, T& x, T& y) {
  if(!b) {
    x = 1;
    y = 0;
    return a;
  }
  T d = extgcd(b, a % b, y, x);
  y -= (a / b) * x;
  return d;
}
//ax+by=gcd(a,b)を満たすx,y 返り値はgcd

template <typename T>
pair<T, T> ChineseRem(const vector<T>& b, const vector<T>& m) {
  T r = 0, M = 1;
  for(int i = 0; i < (int)m.size(); ++i) {
    T p, q;
    T g = extgcd(M, m[i], p, q);
    if((b[i] - r) % g) return {0, -1};
    r += M * (((b[i] - r) / g * p) % (m[i] / g));
    M *= m[i] / g;
  }
  return {(r % M + M) % M, M};
}
//x=a[i](modm[i]) を満たすx(0<=x<Π(m[i])) を求める
//法が互いに素でない場合、解が存在しない場合がある(p.sc==-1を返す)

signed main() {
  cin.tie(0);
  cerr.tie(0);
  ios::sync_with_stdio(false);
  cout << fixed << setprecision(20);
  ll n;
  cin >> n;
  ll m;
  cin >> m;
  ll k;
  cin >> k;
  V<ll> a(n), b(m);
  cin >> a >> b;

  ll sz = 2 * max(n, m) + 5;

  V<ll> aid(sz, -1), bid = aid;
  rep(i, 0, n) aid[a[i]] = i;
  rep(i, 0, m) bid[b[i]] = i;

  ll t = n * m / (gcd(n, m));

  V<ll> samt(0);
  rep(i, 0, sz) {
    if(aid[i] >= 0 && bid[i] >= 0) {
      V<ll> bs = {aid[i], bid[i]};
      V<ll> ms = {n, m};

      PL p = ChineseRem(bs, ms);
      if(p.sc>=0){
        samt.eb(p.fs);
      }
    }
  }

  sort(all(samt));

  ll ok = -1, ng = LINF, md;
  while(abs(ok - ng) > 1) {
    md = (ok + ng) / 2;

    ll dif, sam = 0;

    sam += siz(samt) * (md / t);
    sam += ub(samt, md % t);
    dif = md+1 - sam;

    if(dif >= k)
      ng = md;
    else
      ok = md;
  }
  cout << ng+1 << ENDL;
}
//(・_・)(・_・)(・_・)(・_・)
//CHECK overflow,what to output?
//any other simpler approach?