#include <bits/stdc++.h>
#include <vector>
#define nmax 100005

using namespace std;

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

vector<int> graf[nmax];

int n, m, x, y, cnt;

bool viz[nmax];

/*int cmmdc_i(int a, int b)
{
    int aux;
    if(a<b)
        swap(a,b);
    while(b>0)
    {
        a = a%b;
        aux = a;
        a = b;
        b = aux;
    }
    return a;
}

int cmmdc_r(int a, int b)
{
    if(b==0)
        return a;
    else
        cmmdc_r(b, a%b);
}*/

void dfs(int nod)
{
     viz[nod] = 1;
    for(int i=0; i<graf[nod].size(); i++)
    {
        if(viz[graf[nod][i]]==0)
        {
            dfs(graf[nod][i]);
        }
    }
}

int main()
{
    in>>n>>m;
    for(int i=1; i<=m; i++)
    {
        in>>x>>y;
        graf[x].push_back(y);
        graf[y].push_back(x);
    }
    for(int i=1; i<=n; i++)
    {
        if(viz[i]==0)
        {
            dfs(i);
            cnt++;
        }
    }
    out<<cnt;
    return 0;
}