#include <iostream>
#include <cstdio>
#include <vector>
#define NMAX 100005

using namespace std;

int N, M;
bool viz[NMAX];
vector <int> G[NMAX];

void read()
{
    scanf("%d %d", &N, &M);
    for(int i=1; i<=M; ++i)
    {
        int a, b;
        scanf("%d %d", &a, &b);
        G[a].push_back(b);
        G[b].push_back(a);
    }
}

void dfs(int nod)
{
    vector <int>::iterator it;
    viz[nod] = true;
    for(it = G[nod].begin(); it != G[nod].end(); ++it)
        if(viz[*it] == false)
            dfs(*it);
}

void solvePrint()
{
    int nrComponente = 0;
    for(int i=1; i<=N; ++i)
        if(viz[i] == false)
        {
            dfs(i);
            nrComponente++;
        }
    printf("%d", nrComponente);
}

int main()
{
    freopen("dfs.in", "r", stdin);
    freopen("dfs.out", "w", stdout);
    read();
    solvePrint();
    return 0;
}