#include <iostream>
#include <fstream>
#include <vector>
#include <queue>
using namespace std;
ifstream in("dfs.in");
ofstream out("dfs.out");
const int N=100001;
vector<int> a[N];
queue<int> q;
int n,m;
bool v[N];
void citire()
{
    int x,y;
    in>>n>>m;
    for(int i=0;i<m;i++)
    {
        in>>x>>y;
        a[x].push_back(y);
        a[y].push_back(x);
    }
}
void dfs(int x)
{
    v[x]=true;
    for(size_t i=0;i<a[x].size();i++)
        if(!v[a[x][i]])
            dfs(a[x][i]);
}
int main()
{
    int s=0;
    citire();
    for(int i=1;i<=n;i++)
        if(!v[i]){
            dfs(i);
            s++;
        }
    out<<s;
    return 0;
}