#include <iostream>
#include <map>
#include <vector>
using namespace std;
typedef long long ll;
const ll mod = 1000000007LL;
map< int, vector<int> > neigh;
map< int, bool > vis;
vector<int> special_vertices;
int times_mod(int a, int b, ll mod) {
return ll(a) * ll(b) % mod;
}
// solves a*x + b*y = d = gcd(a, b)
// if d == 1, x is a modular inverse of a mod b
void extended_gcd(ll a, ll b, ll &d, ll &x, ll &y)
{
if(a < 0) {extended_gcd(-a, b, d, x, y); x *= -1; return;}
if(b < 0) {extended_gcd(a, -b, d, x, y); y *= -1; return;}
x = 0, y = 1;
ll lx = 1, ly = 0, frac, tmp;
while(b)
{
frac = a / b;
tmp = a; a = b; b = tmp % b;
tmp = x; x = lx - frac * x; lx = tmp;
tmp = y; y = ly - frac * y; ly = tmp;
}
x = lx; y = ly; d = a;
}
// calculates x^-1 mod a
ll inv_mod(ll x, ll a)
{
ll res, y, d;
extended_gcd(x, a, d, res, y);
return ((res % a) + a) % a;
}
ll pow_mod(ll a, ll b, ll n)
{
if(b < 0) return inv_mod(pow_mod(a, -b, n), n);
ll t, result = 1;
for(t = a % n; b; t = times_mod(t, t, n), b >>= 1)
if(b & 1) result = times_mod(result, t, n);
return result;
}
void dfs(int v, int &num_vertex, int &sum_deg) {
vis[v] = true;
num_vertex++;
vector<int> &vneigh = neigh[v];
for (int i = 0; i < int(vneigh.size()); i++) {
int u = vneigh[i];
if(!vis[u])
dfs(u, num_vertex, sum_deg);
sum_deg++;
}
}
int n, m;
int main() {
cin >> n >> m;
while(m--) {
int a, b;
cin >> a >> b;
neigh[a].push_back(b);
neigh[b].push_back(a);
special_vertices.push_back(a);
special_vertices.push_back(b);
}
int c = n;
vector<int> e;
for (int i = 0; i < int(special_vertices.size()); i++) {
int v = special_vertices[i];
if (!vis[v]) {
int num_vertex = 0, sum_deg = 0;
dfs(v, num_vertex, sum_deg);
if (2 * (num_vertex - 1) != sum_deg) {
cout << 0 << endl;
return 0;
}
c -= (num_vertex - 1);
e.push_back(num_vertex);
}
}
/*
cout << c << endl;
for (int i = 0; i < int(e.size()); i++)
cout << e[i] << " ";
cout << endl;
*/
if (c == 1)
cout << 1 << endl;
else {
int ans = pow_mod(n, c - 2, mod);
for (int i = 0; i < int(e.size()); i++)
ans = times_mod(ans, e[i], mod);
cout << ans << endl;
}
return 0;
}
