#include <bits/stdc++.h>

using namespace std;
	
ifstream f("dfs.in");
ofstream g("dfs.out");
	
int n, m, components;
vector<int> node[100005];
int visited[100005];
	
void dfs(int n){
    visited[n] = 1;
    for(auto i : node[n]){
        if(visited[i] == 0){
            dfs(i);
        }
    }
}
int main()
{
    int x, y;
    f>>n>>m;
    for(int i = 1; i <= m; i++){
        f>>x>>y;
        node[x].push_back(y);
        node[y].push_back(x);
    }
    for(int i = 1; i <= n; i++){
        if(visited[i] ==0){
            components++;
            dfs(i);
        }
    }
    g<<components;
    return 0;
}