#include <iostream>
#include <fstream>
#include <map>
#include <vector>

using namespace std;

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

map<int,vector<int> > graph ;
map<int,bool> visited ;
int n,m;

void df(int x){
    int i;
    visited[x]=true;
    for(i=0;i<graph[x].size();++i){
        if(!visited[graph[x][i]]){
            df(graph[x][i]);
        }
    }
}

int main()
{
    in>>n>>m;
    int x,y,i;
    for(i=1;i<=m;++i){
        in>>x>>y;
        graph[x].push_back(y);
        graph[y].push_back(x);
    }
    int conexComp=0;
    for(i=1;i<=n;++i){
        if(!visited[i]){
            conexComp++;
            df(i);
        }
    }
    out<<conexComp;
    return 0;
}