#include <stdio.h>
#include <map>
#include <utility>
using namespace std;
const int MOD = 1000000007;
map<int, int> par;
map<int, int> cnt;
int getroot(int x){
if(par.find(x) == par.end()) par[x] = x;
if(par[x] == x) return x;
return (par[x] = getroot(par[x]));
}
int mul(int x, int y){ return (long long)x * y % MOD; }
int power(int x, int y){
if(y == 0) return 1;
int r = power(x, y / 2);
r = mul(r, r);
if(y % 2 == 1) r = mul(r, x);
return r;
}
int main(){
int N, M; scanf("%d%d", &N, &M);
bool val = true;
for(int i = 1; i <= M; i++){
int x, y; scanf("%d%d", &x, &y);
int px = getroot(x), py = getroot(y);
if(px == py) val = false;
else par[px] = py;
}
if(!val){ puts("0"); }
else{
for(pair<int, int> pp : par){
int x = pp.first;
cnt[getroot(x)]++;
}
int NN = N - (int)par.size() + (int)cnt.size();
int ans = 1;
if(NN != 1){
for(pair<int, int> pp : cnt) ans = mul(ans, pp.second);
ans = mul(ans, power(N, NN - 2));
}
printf("%d\n", ans);
}
return 0;
}
