#include <bits/stdc++.h>

#define NMax 100005

using namespace std;

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

int N,M;
vector<int> G[NMax];
bool visited[NMax];

void DFS(int node)
{
    visited[node]=true;
    for(auto child : G[node])
        if(!visited[child])
            DFS(child);
}

int main()
{
    fin>>N>>M;
    for(int i=1;i<=M;i++)
    {
        int x,y;
        fin>>x>>y;
        G[x].push_back(y);
        G[y].push_back(x);
    }

    int conexe=0;
    for(int i=1;i<=N;i++)
        if(!visited[i])
            conexe++, DFS(i);
    fout<<conexe;

    return 0;
}