#include <bits/stdc++.h>

using namespace std;
ifstream f("dfs.in");
ofstream g("dfs.out");
int n,m,x,y;
int nrc;
bool viz[100001];

vector<vector<int>> a(100001,vector<int>());

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

int main()
{
    f>>n>>m;
    for(int i=1;i<=m;++i)
    {
        f>>x>>y;
        a[x].push_back(y);
        a[y].push_back(x);
    }
    for(int i=1;i<=n;++i)
        if(!viz[i])
        {
            ++nrc;
            DFS(i);
        }
    g<<nrc;
    return 0;
}