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

ifstream f("dfs.in");
ofstream g("dfs.out");

#define pb push_back

const int N = 1e5 + 5;
const int oo = 1e9;

int n, m, x, y;
bool u[N];
vector<int> v[N];

void read(), dfs(int);

int main()
{
    read();
    x = 0;
    for (int i = 1; i <= n; i++)
        if (!u[i]){
            x++;
            dfs(i);
        }
    g << x;
    
    return 0;
}

void read(){
    f >> n >> m;
    for (; m; m--){
        f >> x >> y;
        v[x].pb(y);
        v[y].pb(x);
    }
}
void dfs(int nod){
    u[nod] = 1;
    for (auto it : v[nod])
        if(!u[it]) dfs(it);
}