#include<cstdio>
#include<iostream>
#include<algorithm>
#include<vector>
#define RI register int
#define CI const int&
using namespace std;
const int N=500005;
struct edge
{
	int x,y,z;
	friend inline bool operator < (const edge& A,const edge& B)
	{
		return A.z<B.z;
	}
}; int n,m,q,ans,x[N],y[N],z[N],u[N],v[N],sp[N],fa[N],bel[N],rst[N],vis[N];
inline int getfa(CI x)
{
	return fa[x]!=x?fa[x]=getfa(fa[x]):x;
}
inline void merge(CI x,CI y)
{
	fa[getfa(x)]=getfa(y);
}
int main()
{
	//freopen("D.in","r",stdin); freopen("D.out","w",stdout);
	RI i,j; for (scanf("%d%d",&n,&m),i=1;i<=m;++i)
	scanf("%d%d%d",&x[i],&y[i],&z[i]);
	for (i=1;i<=n;++i) fa[i]=i;
	for (i=1;i<=m;++i) merge(x[i],y[i]);
	for (i=2;i<=n;++i) if (getfa(i)!=getfa(1)) return puts("-1"),0;
	for (scanf("%d",&q),i=0;i<q;++i)
	scanf("%d%d",&u[i],&v[i]),sp[u[i]]=sp[v[i]]=1;
	for (i=1;i<=n;++i) fa[i]=i; vector <edge> E;
	for (i=1;i<=m;++i) if (sp[i]) merge(x[i],y[i]);
	else E.push_back((edge){x[i],y[i],z[i]});
	sort(E.begin(),E.end()); vector <edge> cs;
	for (auto [x,y,z]:E)
	{
		if (getfa(x)==getfa(y)) continue;
		cs.push_back((edge){x,y,z}); merge(x,y); ans+=z;
	}
	for (i=1;i<=n;++i) fa[i]=i;
	for (auto [x,y,z]:cs) merge(x,y);
	int idx=0; for (i=1;i<=n;++i)
	{
		int tmp=getfa(i); if (!rst[tmp]) rst[tmp]=++idx; bel[i]=rst[tmp];
	}
	int ret=1e9; for (i=0;i<(1<<q);++i)
	{
		for (j=1;j<=idx;++j) fa[j]=j; int cur=0;
		for (j=0;j<q;++j) vis[u[j]]=vis[v[j]]=0;
		vector <edge> left; for (j=0;j<q;++j)
		if ((i>>j)&1)
		{
			if (!vis[v[j]]) cur+=z[v[j]],vis[v[j]]=1; merge(bel[x[v[j]]],bel[y[v[j]]]);
			left.push_back((edge){bel[x[u[j]]],bel[y[u[j]]],z[u[j]]});
		} else
		{
			if (!vis[u[j]]) cur+=z[u[j]],vis[u[j]]=1; merge(bel[x[u[j]]],bel[y[u[j]]]);
			left.push_back((edge){bel[x[v[j]]],bel[y[v[j]]],z[v[j]]});
		}
		sort(left.begin(),left.end());
		for (auto [x,y,z]:left)
		{
			if (getfa(x)==getfa(y)) continue; merge(x,y); cur+=z;
		}
		ret=min(ret,cur);
	}
	return printf("%d",ans+ret),0;
}