#include <iostream>
#include <fstream>
#include <vector>
using namespace std;
ifstream in("dfs.in");
ofstream out ("dfs.out");
vector<int>v[100005];
int viz[100005];
int a,b,n,m,cnt=0;

void dfs(int nod)
{
    viz[nod]=1;
    int i;
    for( i=0;i<v[nod].size();++i)
        if(!viz[v[nod][i]])
            dfs(v[nod][i]);
}

int main()
{
    in>>n>>m;
    for(int i=1;i<=m;++i)
    {
        in>>a>>b;
        v[a].push_back(b);
        v[b].push_back(a);
    }
    for(int i=1;i<=n;++i)
    {
        if(viz[i]==0)
        {
            dfs(i);
            cnt++;
        }


    }
    out<<cnt;
    return 0;
}