#include<bits/stdc++.h>
using namespace std;
typedef long long LL;
const int N=(int)5000;
const int M=40000;
vector<int>ke[N+2];
LL d[N+2][N+2]={};
int dd[N+2][N+2]={},u[M+2],v[M+2],a[M+2],b[M+2];
int n,m,k;
void djisktra(int source){
queue<int>q;
for(int i=1;i<=n;++i) dd[source][i]=-1;
dd[source][source]=0;
d[source][source]=1;
q.push(source);
while (q.size()){
int u=q.front(); q.pop();
for(auto&v:ke[u]){
if (dd[source][v]==-1){
d[source][v]=d[source][u];
dd[source][v]=dd[source][u]+1;
q.push(v);
}
else if (dd[source][v]==dd[source][u]+1) d[source][v]+=d[source][u];
}
}
return;
}
void add_canh(int u,int v){
ke[u].push_back(v),
ke[v].push_back(u);
return;
}
int main(){
ios::sync_with_stdio(false);
cin.tie(0) ; cout.tie(0);
// freopen("main.inp","r",stdin);
cin>>n>>m;
for(int i=1;i<=m;++i){
cin>>u[i]>>v[i];
++u[i],++v[i];
add_canh(u[i],v[i]);
}
for(int i=1;i<=n;++i) djisktra(i);
cin>>k;
for(int i=1;i<=k;++i) {
cin>>a[i]>>b[i];
++a[i],++b[i];
}
double cur=0;
int ans=-1;
for(int i=1;i<=n;++i){
double x=0;
for(int j=1;j<=k;++j){
int s2=d[a[j]][b[j]];
int s1=0;
if (dd[a[j]][i]+dd[b[j]][i]==dd[a[j]][b[j]]) s1=d[a[j]][i]*d[b[j]][i];
if (s2!=0) x+=(double)s1/s2;
}
if (cur<x){
cur=x;
ans=i;
}
}
cout<<ans-1;
}
