#include <bits/stdc++.h>

using namespace std;

ifstream in;
ofstream out;

vector<vector<int>> edge;
vector<bool> ap;

void DFS(int start)
{
    ap[start]=1;
    for(auto & it:edge[start])
    {
        if(!ap[it])
            DFS(it);
    }
}
int n,m;
int main()
{
    in.open("dfs.in");
    out.open("dfs.out");
    
    in>>n>>m;
    edge.resize(n+1);
    ap.resize(n+1);
    for(int i=1;i<=m;i++)
    {
        int x,y;
        in>>x>>y;
        edge[x].push_back(y);
        edge[y].push_back(x);
    }
    int nr=0;
    for(int i=1;i<=n;i++)
    {
        if(ap[i]==0)
        {
            DFS(i);
            nr++;
        }
    }
    out<<nr;
    return 0;
}