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

using namespace std;

int n, m, viz[NMAX];
vector <int> g[NMAX];
vector <int>::iterator it;
stack <int> s;

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

void dfs(int nodPornire)
{
    int nod;
    s.push(nodPornire);
    viz[nodPornire]=1;
    while(!s.empty())
    {
        nod=s.top();
        s.pop();
        for(it=g[nod].begin(); it!=g[nod].end(); ++it)
            if(viz[*it]==0)
            {
                s.push(*it);
                viz[*it]=1;
            }
    }
}

int main()
{
    freopen("dfs.in", "r", stdin);
    freopen("dfs.out", "w", stdout);
    read();
    int nrComponente=0;
    for(int i=1; i<=n; ++i)
        if(viz[i]==0)
        {
            dfs(i);
            nrComponente++;
        }
    printf("%d", nrComponente);
    return 0;
}