#include <bits/stdc++.h>
using namespace std;

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

int n,m,viz[100001],nrc;
vector <int> v[100001];

void df(int x)
{
    viz[x]=nrc;
    for(int j=0; j<v[x].size(); j++)
    {
        int vecin=v[x][j];
        if(!viz[vecin])
            df(vecin);
    }
}
void citire()
{
    f>>n>>m;
    for(int i=1; i<=m; i++)
    {
        int x,y;
        f>>x>>y;
        v[x].push_back(y);
        v[y].push_back(x);
    }
}
int main()
{
    citire();
    for(int i=1; i<=n; ++i)
        if(!viz[i])
        {
            nrc++;
            df(i);
        }
    g<<nrc;
}