#include <cstdio>
#include <map>
const int p = 1000000007;
using namespace std;
int pw(int x, int y)
{
return y & 1 ? (long long)pw(x, y ^ 1)*x%p : y ? pw((long long)x*x%p, y >> 1) : 1;
}
map<int, int> M, S;
int f(int x)
{
if (M.find(x) == M.end()) M[x] = x;
int t = M[x];
return x == t ? x : M[x] = f(t);
}
void g(int x, int y)
{
x = f(x);
y = f(y);
if (S.find(x) == S.end()) S[x] = 1;
if (S.find(y) == S.end()) S[y] = 1;
S[x] += S[y];
M[y] = M[x];
}
int main()
{
map<int, int>::iterator it;
int i, j, k, n, m, r;
scanf("%d%d", &n, &m);
for (k = 0; k < m;k++)
{
scanf("%d%d", &i, &j);
if (f(i) == f(j))
{
puts("0");
return 0;
}
g(i, j);
}
if (m == n - 1)
{
puts("1");
return 0;
}
r = pw(n, n - m - 2);
for (it = S.begin(); it != S.end(); it++) if (it->first == f(it->first)) r = (long long)r * it->second % p;
printf("%d", r);
}
