#include <bits/stdc++.h>
#define ll long long
#define ull unsigned long long
#define ld long double
#define chad char
#define mod 1'000'000'007
#define dim 100005
#define lim 1000000
#define mdim 1501
#define mult 2e9
#define maxx 200002
#define simaimult 1e17
#define FOR(i,a,b) for(int i=(a); i<=(b); i++)
#define pli pair<ll,int>
#define pil pair<int,ll>
#define piii pair<int,pair<int,int> >
#define pii pair<int,int>
#define pll pair<ll,ll>
#define pb push_back
#define mp make_pair
#define nr_biti __builtin_popcount
using namespace std;

ifstream fin("dfs.in");
ofstream fout("dfs.out");

int n,m;
bool viz[2*dim];

vector<int> g[dim];

void dfs(int nod)
{
    viz[nod]=1;

    for(auto it:g[nod])
        if(!viz[it]) dfs(it);
}

int main()
{
    ios_base::sync_with_stdio(false);
    fin.tie(nullptr);
    fout.tie(nullptr);

    fin >> n >> m;

    for(int i=1; i<=m; i++)
    {
        int x,y;

        fin >> x >> y;

        g[x].pb(y);
        g[y].pb(x);
    }

    int cnt=0;

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

    fout << cnt;

    return 0;
}