#include <bits/stdc++.h>
#define NMAX 100001

using namespace std;
ifstream inp("bfs.in");
ofstream out("bfs.out");

vector<int> G[NMAX];
int n, m, c, viz[NMAX];

void DFS(int nod)
{
    viz[nod] = 1;
    int nrnod = G[nod].size();
    int nodc;
    for(int i = 0; i < nrnod; ++i)
    {
        nodc = G[nod][i];
        if(viz[nodc] == 0)
            DFS(nodc);
    }
}

int main()
{
    inp >> n >> m;
    int x, y;
    for(int i = 1; i <= m; i++) {
        inp >> x >> y;
        G[x].push_back(y);
        G[y].push_back(x);
    }

    for(int nod = 1; nod <= n; nod++)
        if(viz[nod] == 0)
        {
            c++;
            DFS(nod);
        }
    out << c;
}

/*#include <iostream>
#include <stdio.h>
#define NMAX 20000
#define MMAX 20000
using namespace std;

int n, m;
int a[NMAX][MMAX];
int viz[NMAX];

void DFS(int nod)
{
    viz[nod] = 1;
    for(int i = 1; i <= n; i++)
        if(viz[i] != 1 && a[nod][i] != 0)
            DFS(i);
}

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

    scanf("%d %d", &n, &m);
    int i, x, y;
    for(i = 1; i <= n; ++i)
    {
        scanf("%d %d", &x, &y);
        a[x][y] = a[y][x] = 1;
    }

    int comp = 0;
    for(i = 1; i <= n; ++i)
        if(viz[i] != 1)
        {
            comp++;
            DFS(i);
        }
    printf("%d", comp);

    return 0;
}*/