just_one

//#include<bits/stdc++.h>
#include<iostream>
#include<cstdlib>
#include<vector>
#include<queue>
#include<set>

#define long long long
#define nln '\n'

const long N = 2*1e5+1;

using namespace std;

vector<bool> pic;
vector<long> vtx;
vector<vector<long>> mat(N);
long mul, ans, vec = 0, edg = 0;

void dfs(long i)
{
    pic[i] = 1;
    ++vec;
    edg += vtx[i];
    for (const auto j : mat[i])
        if (!pic[j])
        {
            dfs(j);
            break;
        }
}

int main()
{
    //freopen("just_one.inp", "r", stdin);
    long n, m;
    cin >> n >> m;
    vtx.resize(n+1, 0);
    for (long i = 1; i <= m; ++i)
    {
        long x, y;
        cin >> x >> y;
        ++vtx[x]; ++vtx[y];
        mat[x].push_back(y);
        mat[y].push_back(x);
    }

    pic.resize(n+1, 0);
    ans = 1;
    for (long i = 1; i <= n; ++i)
    {
        if (!pic[i])
        {
            ans *= 2;
            vec = 0; edg = 0;
            dfs(i);
            if (vec*2 != edg)
            {
                ans = 0;
                break;
            }
        }
    }

    cout << ans << nln;
    return 0;
}