#include <iostream>
#include <iomanip>
#include <vector>
#include <cmath>
#include <algorithm>
#include <set>
#include <queue>
#include <map>
#include <stack>
#include <bitset>
#include <string>
#include <cstring>
#include <iterator>
#include <random>
using namespace std;
typedef long long ll;
typedef pair<ll, ll> pll;
typedef long double ld;
const ll dim = 5*(1e3)+7;
//const ll mod = 1e9 + 7;
const ll inf = 1e18 + 77;
#define endl "\n"
#define fi first
#define pb push_back
#define se second
#define vll vector<ll>
ll n, m;
ll t=0;
vector<ll> a[dim];
ll tin[dim], tout[dim], depth[dim], sum[dim];
ll dst[dim][dim];
ll cntw[dim][dim];
int main() {
cin>>n>>m;
for(int i=1; i<=m; i++){
ll u, v, w;
cin>>u>>v;
u++;
v++;
a[u].pb(v);
a[v].pb(u);
}
ll k;
vector<pll> pr;
cin>>k;
for(int i=1; i<=k; i++){
ll u, v;
cin>>u>>v;
u++;
v++;
pr.pb({u, v});
}
for(int i=1; i<=n; i++){
for(int j=1; j<=n; j++){
dst[i][j]=inf;
}
}
for(int u=1; u<=n; u++){
queue<pll> q;
dst[u][u]=0;
q.push({u, 1});
while(q.size()>0){
ll v=q.front().fi;
ll ways=q.front().se;
q.pop();
if(ways<cntw[u][v]){
continue;
}
// vis[v]=1;
for(auto x: a[v]){
ll cur=dst[u][v]+1;
if(cur<dst[u][x]){
dst[u][x]=cur;
cntw[u][x]=ways;
q.push({x, ways});
}
else if(cur==dst[u][x]){
dst[u][x]=cur;
cntw[u][x]+=ways;
q.push({x, cntw[u][x]});
}
}
}
}
ll id=1;
ld ans=0;
for(int e=1;e<=n; e++){
ld od=0;
for(auto [u, v]: pr){
if(dst[e][u]+dst[e][v]!=dst[u][v])continue;
ld cur=(ld)(cntw[e][u]*cntw[e][v])/((ld)cntw[u][v]);
//cout<<fixed<<setprecision(10)<<cur<<endl;
od+=cur;
}
if(od>ans){
ans=od;
id=e;
}
}
id--;
cout<<id<<endl;
return 0;
}
