#include <iostream>
#include <fstream>
#include <vector>
#define MAX 100002
using namespace std;
int n,m,x,y,vf[MAX];
vector<int> v[MAX];

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

void dfs(int nod){
    vf[nod] = 1;
    for(auto fiu: v[nod]){
        if(vf[fiu] == 0)
            dfs(fiu);
    }
}

int main()
{
    fin >> n >> m;
    for(int i = 1; i <= m; i++){
        fin >> x >> y;
        v[x].push_back(y);
        v[y].push_back(x);
    }
    int ans = 0;
    for(int i = 1; i <= n; i++){
        if(vf[i] == 0){
            dfs(i);
            ans++;
        }
    }
    fout << ans;
    return 0;
}