#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <memory.h>
#include <math.h>
#include <assert.h>
#include <stack>
#include <queue>
#include <map>
#include <set>
#include <string>
#include <algorithm>
#include <iostream>
#include <functional>
#include <unordered_map>
#include <unordered_set>
using namespace std;
typedef long long ll;
typedef pair<int, int> Pi;
#define Fi first
#define Se second
#define pb(x) push_back(x)
#define sz(x) (int)x.size()
#define rep(i,n) for(int i=0;i<n;i++)
#define all(x) x.begin(),x.end()
const ll MOD = 1e9 + 7;
ll pw(ll x, ll y){
ll res = 1;
while(y){
if(y & 1)res = res * x % MOD;
x = x * x % MOD;
y >>= 1;
}
return res;
}
map <int, int> M;
int cn;
int par[200020], w[200020];
int Find(int x){return par[x] == x ? x : par[x] = Find(par[x]);}
int q[100010][2];
int main(){
int n, m;
scanf("%d%d", &n, &m);
rep(i, m){
int x, y;
scanf("%d%d", &x, &y);
if(M.find(x) == M.end())M[x] = ++cn;
if(M.find(y) == M.end())M[y] = ++cn;
q[i][0] = M[x], q[i][1] = M[y];
}
for(int i=1;i<=cn;i++)par[i] = i, w[i] = 1;
int ok = 1;
for(int i=0;i<m;i++){
int a = q[i][0], b = q[i][1];
a = Find(a), b = Find(b);
if(a == b){
ok = 0;
break;
}
par[a] = b;
w[b] += w[a];
}
if(!ok){
printf("0");
return 0;
}
else{
ll ans = 1, sum = n - cn;
int cnt = n - cn;
for(int i=1;i<=cn;i++){
if(Find(i) == i){
ans = ans * w[i] % MOD;
sum = (sum + w[i]) % MOD;
cnt++;
}
}
if(cnt > 1)ans = ans * pw(sum, cnt-2) % MOD;
else ans = 1;
printf("%lld", ans);
}
return 0;
}
