#include <bits/stdc++.h>
using namespace std;
ifstream f("dfs.in");
ofstream g("dfs.out");

int N, M, A, B, result;

void DFS(int node, vector<vector<int> > L, vector<bool> &visited)
{
    visited[node] = true;
    for(auto neighbour : L[node])
    {
        if(!visited[neighbour])
        {
            DFS(neighbour,L,visited);
        }
    }
}

int main()
{
    f>>N>>M;
    vector<vector<int> > L(N+1);
    for(int i = 0; i < M; i++)
    {
        f>>A>>B;
        L[A].push_back(B); L[B].push_back(A);
    }
    f.close();
    vector<bool> visited(N+1,false);
    for(int i = 1; i <= N; i++)
    {
        if(visited[i] == false)
        {
            DFS(i,L,visited);
            result++;
        }
    }
    g<<result;
    g.close();
    return 0;
}