#include<cstdio>
#include<fstream>
#include<iostream>
#include<iomanip>
#include<algorithm>
#include<vector>
#include<bitset>
#include<deque>
#include<queue>
#include<set>
#include<map>
#include<cmath>
#include<cstring>
#include<ctime>
#include<cstdlib>
#include<unordered_map>

#define ll long long
#define pb push_back
#define mp make_pair
#define pii pair<int,int>
#define pll pair<ll,ll>

using namespace std;

const int nmax = 100005;

int n, m, x, y, i, sol;

vector<int> v[nmax];
bitset<nmax> viz;

void dfs(int x)
{
    viz[x] = 1;
    for(auto it : v[x])
        if(!viz[it])
            dfs(it);
}

int main()
{
    freopen("dfs.in", "r", stdin);
    freopen("dfs.out", "w", stdout);

    scanf("%d%d", &n, &m);

    for(; m; m--)
    {
        scanf("%d%d", &x, &y);
        v[x].pb(y);
        v[y].pb(x);
    }

    for(i = 1; i <= n; i++)
        if(!viz[i])
        {
            sol++;
            dfs(i);
        }

    printf("%d\n", sol);

    return 0;
}