#include <bits/stdc++.h>
#define whlie while
#define pb push_back
#define eb emplace
#define fi first
#define se second
#define rep(i,N) for(int i = 0; i < (N); i++)
#define repr(i,N) for(int i = (N) - 1; i >= 0; i--)
#define rep1(i,N) for(int i = 1; i <= (N) ; i++)
#define repr1(i,N) for(int i = (N) ; i > 0 ; i--)
#define each(x,v) for(auto& x : v)
#define all(v) (v).begin(),(v).end()
#define sz(v) ((int)(v).size())
#define ini(...) int __VA_ARGS__; in(__VA_ARGS__)
#define inl(...) ll __VA_ARGS__; in(__VA_ARGS__)
#define ins(...) string __VA_ARGS__; in(__VA_ARGS__)
using namespace std; void solve();
using ll = long long; using vl = vector<ll>;
using vi = vector<int>; using vvi = vector< vector<int> >;
constexpr int inf = 1001001001;
constexpr ll infLL = (1LL << 61) - 1;
struct IoSetupNya {IoSetupNya() { cin.tie(nullptr); ios::sync_with_stdio(false); cout << fixed << setprecision(15); cerr << fixed << setprecision(10);} } iosetupnya;
template<typename T, typename U> inline bool amin(T &x, U y) { return (y < x) ? (x = y, true) : false; }
template<typename T, typename U> inline bool amax(T &x, U y) { return (x < y) ? (x = y, true) : false; }
template<typename T, typename U> ostream& operator <<(ostream& os, const pair<T, U> &p) { os << p.first << " " << p.second; return os; }
template<typename T, typename U> istream& operator >>(istream& is, pair<T, U> &p) { is >> p.first >> p.second; return is; }
template<typename T> ostream& operator <<(ostream& os, const vector<T> &v) { int s = (int)v.size(); rep(i,s) os << (i ? " " : "") << v[i]; return os; }
template<typename T> istream& operator >>(istream& is, vector<T> &v) { for(auto &x : v) is >> x; return is; }
void in(){} template <typename T,class... U> void in(T &t,U &...u){ cin >> t; in(u...);}
void out(){cout << "\n";} template <typename T,class... U> void out(const T &t,const U &...u){ cout << t; if(sizeof...(u)) cout << " "; out(u...);}
template<typename T>void die(T x){out(x); exit(0);}
#ifdef NyaanDebug
  #include "NyaanDebug.h"
  #define trc(...) do { cerr << #__VA_ARGS__ << " = "; dbg_out(__VA_ARGS__);} while(0)
  #define trca(v,N) do { cerr << #v << " = "; array_out(v , N);cout << endl;} while(0)
#else
  #define trc(...)
  #define trca(...)
  int main(){solve();}
#endif
using P = pair<int,int>; using vp = vector<P>;
constexpr int MOD = /** 1000000007; //*/ 998244353;
////////////////



void solve(){
  ini(X , Y , Z , N , M , S , T);
  vp A(N) , B(M); in(A , B);
  S--; T--;

  auto idx = [&](int shu , int idx){
    if(shu == 0) return idx;
    if(shu == 1) return X + idx;
    if(shu == 2) return X + Y + idx;
    if(shu == 3) return X + Y + Z + idx;
    if(shu == 4) return X + Y + Z + N + idx;
    trc("error");
    exit(1);
  };

  vvi g(X + Y + Z + N + M);
  auto add = [&](int a,int b){g[a].pb(b) ; g[b].pb(a);};
  rep(i , N){
    // カツサンド
    add( idx( 3 , i ) , idx (0 , A[i].fi - 1) );
    add( idx( 3 , i ) , idx (1 , A[i].se - 1) );
  }
  rep(i , M){
    // アレ
    add( idx( 4 , i ) , idx (1 , B[i].fi - 1) );
    add( idx( 4 , i ) , idx (2 , B[i].se - 1) );
  }
  
  A.clear(); A.shrink_to_fit();
  B.clear(); B.shrink_to_fit();

  // 幅優先
  int start = idx(3 , S) , goal = idx(4 , T);
  vi visited(X + Y + Z + N + M , 0);
  vi d(X + Y + Z + N + M , -1);
  queue<int> Q;
  Q.push(start); d[start] = 0; visited[start] = 1;
  while(!Q.empty()){
    int cur = Q.front(); Q.pop();
    if(cur == goal) die(d[cur] / 2);
    each(x , g[cur]){
      if(visited[x] == 1) continue;
      visited[x] = 1 , d[x] = d[cur] + 1;
      Q.push(x);
    }
  }
  out(-1);
  

  

}


Measured memory_bytes: 31856