#include <bits/stdc++.h>

using namespace std;
ifstream f("dfs.in");
ofstream g("dfs.out");
const int nMax = 100003;
vector <int> Graf[nMax];
bool viz[nMax];
int ans;
inline void Dfs(int nod) {
    viz[nod] = 1;
    for(const auto &i : Graf[nod]) {
        if(!viz[i]) {
            Dfs(i);
        }
    }
}
int main()
{
    int n, m, x, y;
    f >> n >> m;
    for(int i = 1; i <= m; i++) {
        f >> x >> y;
        Graf[x].push_back(y);
        Graf[y].push_back(x);
    }
    for(int i = 1; i <= n; i++) {
        if(!viz[i]) {
            Dfs(i);
            ans++;
        }
    }
    g << ans << "\n";
    return 0;
}