#include <bits/stdc++.h>
#define NMAX 100005
using namespace std;

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

vector < int > nod[NMAX];

int n, m, x, y, ans;
bool visited[NMAX];

void dfs(int node){
    visited[node] = 1;
    for(int i = 0; i < nod[node].size(); ++i)
        if(!visited[nod[node][i]])
            dfs(nod[node][i]);
}

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