#include <bits/stdc++.h>
#define NMAX 100001
using namespace std;
int N,M;
vector<int>v[NMAX];
int fr[NMAX];
int conex;
void dfs(int i)
{
    for(auto x: v[i])
    {
        if(!fr[x])
        {
            fr[x]=1;
            dfs(x);
        }
    }
}
int main()
{
    ifstream fin("dfs.in");
    ofstream fout("dfs.out");
    fin>>N>>M;
    for(int i=1;i<=M;++i)
    {
        int x,y;
        fin>>x>>y;
        v[x].push_back(y);
        v[y].push_back(x);
    }

    for(int i=1;i<=N;++i)
    {
        if(!fr[i])
        {
            conex++;
            dfs(i);
        }
    }
    fout<<conex;
    return 0;
}