#include<bits/stdc++.h>
using namespace std;
#define int long long
#define ld long double
#define inf 5e18
#define nl '\n'
inline void solve(){
int n, m;
cin>>n>>m;
vector<int> g[n];
for(int i=0; i<m; i++){
int a, b;
cin>>a>>b;
g[a].push_back(b);
g[b].push_back(a);
}
int k;
cin>>k;
vector<pair<int,int>> v(k);
for(auto &[a, b] : v) cin>>a>>b;
int d[n][n], c[n][n];
for(int i=0; i<n; i++){
priority_queue<pair<int,int>, vector<pair<int,int>>, greater<pair<int,int>>> pq;
auto &dist = d[i];
auto &cnt = c[i];
pq.push({0, i});
fill(dist, dist+n, inf);
dist[i] = 0;
cnt[i] = 1;
while(!pq.empty()){
auto [dis, v] = pq.top();
pq.pop();
if(dis > dist[v]) continue;
for(int ch : g[v]){
if(dis+1 < dist[ch]){
dist[ch] = dis+1;
cnt[ch] = 1;
pq.push({dist[ch], ch});
}
else if(dis+1 == dist[ch]){
cnt[ch] += cnt[v];
}
}
}
}
int ans = 0;
ld mx = 0;
for(int i=0; i<n; i++){
ld sum = 0;
for(auto [a, b] : v){
if(d[a][i] + d[i][b] == d[a][b]) sum += (c[a][i] * c[i][b])/c[a][b];
}
if(sum > mx){
mx = sum;
ans = i;
}
}
cout<<ans;
}
signed main(){
ios_base::sync_with_stdio(0);
cin.tie(NULL);cout.tie(NULL);
int t = 1;
//cin>>t;
while(t--) solve();
return 0;
}
