#include <iostream>
#include <fstream>
#include <vector>
#define NMAX 100001
using namespace std;
ifstream in("dfs.in");
ofstream out("dfs.out");
vector<int> v[NMAX];
int a[NMAX], n, m, numOfNodes;

void dfs(int node){
    a[node]=1;
    for(unsigned int i=0; i<v[node].size(); i++){
        if(a[v[node][i]]==0)dfs(v[node][i]);
    }
}

void read(){
    in>>n>>m;
    int x, y;
    for(int i=1; i<=m; i++){
        in>>x>>y;
        v[x].push_back(y);
        v[y].push_back(x);
    }
    for(int i=1; i<=n; i++){
        if(a[i]==0){
            dfs(i);
            numOfNodes++;
        }
    }
    out<<numOfNodes;
}

int main(){
    read();
    return 0;
}