#include <bits/stdc++.h>

using namespace std;

ifstream fin("dfs.in");
ofstream fout("dfs.out");
vector<int> a[100002];
int n, m, i, x, y;
bool fr[100002];

static inline void Fill(int nod) {
    fr[nod] = true;
    for(auto it : a[nod]) {
        if(!fr[it]) Fill(it);
    }
}

int main() {
    fin >> n >> m;
    for(i = 1; i <= m; i++) {
        fin >> x >> y;
        a[x].push_back(y);
        a[y].push_back(x);
    }

    for(i = 1; i <= n; i++) {
        if(!fr[i]) {
            Fill(i);
            r++;
        }
    }

    fout << r;

    return 0;
}