#include<bits/stdc++.h>
using namespace std;
const int N=1e5+3,P=1e9+7;
basic_string<int>v[3][N+1];
int iv[N],a[N],o,u;
void in(){
int n,m,i,j;
basic_string<int>ji,ou;
vector<basic_string<int>>g;
queue<int>q;
scanf("%d%d",&n,&m),ji.assign(n+1,N),ou.assign(n+1,N),g.resize(n+1);
while(m--)scanf("%d%d",&i,&j),g[i]+=j,g[j]+=i;
q.push(1),ou[1]=0;
while(q.size()){
i=q.front(),q.pop();
if(i>n){
i-=n;
for(int j:g[i])if(ou[j]==N)ou[j]=ji[i]+1,q.push(j);
}else for(int j:g[i])if(ji[j]N)ji[j]=ou[i]+1,q.push(j+n);
}
for(i=1;i<=n;++i)v[0][ji[i]]+=u,v[1][ou[i]]+=u,v[2][max(ji[i],ou[i])]+=u;
}
int get(basic_string<int>v){
int i,s=0,t=1,c=0;
for(i=0,memset(a,0,N4);i<N;++i)for(int j:v[i]){
if(a[j])t=t1lliv[a[j]]%P;else ++c;
if(co)s=(s+t1lli)%P;
t=t1ll(++a[j])%P;
}
return s;
}
int main(){
for(iv[1]=1,u=2;u<N;++u)iv[u]=(P-P/u)1lliv[P%u]%P;
for(scanf("%d",&o),u=1;u<=o;++u)in();
printf("%d",((get(v[0])+get(v[1])-get(v[2]))%P+P)%P);
return 0;
}
