#include <iostream>
#include <vector>
#include <bitset>

#define NMAX 100005

using namespace std;

int n, m, ans;
bool v[NMAX];
vector<int> adj[NMAX];

inline int dfs(const int X) {
    for(const auto &el : adj[X]) {
        if(!v[el]) {
            v[el] = 1;
            dfs(el);
        }
    }
}

int main()
{
    freopen("dfs.in", "r", stdin);
    freopen("dfs.out", "w", stdout);
    scanf("%d%d", &n, &m);
    for(int x, y; m; --m)  {
        scanf("%d%d", &x, &y);
        adj[x].push_back(y);
        adj[y].push_back(x);
    }
    for(int i = 1; i <= n; ++i) {
        if(!v[i]) {
            ans++;
            v[i] = 1;
            dfs(i);
        }
    }
    printf("%d", ans);
    return 0;
}