#include<vector>
#include<queue>
#include <iostream>
#include <fstream>
 
using namespace std;
 
#define NMAX 100005
 
vector<int> graph[NMAX];
bool viz[NMAX];
int n, m, answer;
ifstream f("dfs.in");
ofstream g("dfs.out");
 
void dfs(int node) {
    if(viz[node])
        return ;
    viz[node] = 1;
    for(auto vecin : graph[node]) {
        dfs(vecin);
    }
}
 
int main() {
    int a, b;
    
    f>>n>>m;
    for(int i = 1; i <= m; i++) {
        f>>a>>b;
        graph[a].push_back(b);
        graph[b].push_back(a);
    }
    
    for(int i = 1; i <= n; i++) {
        if(!viz[i]) {
            dfs(i);
            answer++;
        }
    }
    
    g<<answer;
    
    return 0;
}