#include <cstdio>
#include <vector>
#include <deque>
#define pb push_back
#define NMAX 100001

using namespace std;

FILE *f = freopen("dfs.in", "r", stdin);
FILE *g = freopen("dfs.out", "w", stdout);

vector <int> G[NMAX];
deque <int> q;
bool viz[NMAX];
int n, m;
void bfs(int start) {
    q.pb(start);
    viz[start] = true;

    while(!q.empty()) {
        int nod = q.front();
        q.pop_front();
        for(int i = 0; i<G[nod].size(); i++)
            if(!viz[G[nod][i]]) {
                q.pb(G[nod][i]);
                viz[G[nod][i]] = true;
        }
    }
}
void read() {
    scanf("%d%d", &n, &m);
    for(int i = 1; i<=m; i++) {
        int x, y;
        scanf("%d%d", &x, &y);
        G[x].pb(y);
        G[y].pb(x);
    }
}
int main() {
    int nr = 0;
    read();
    for(int i = 1; i<=n; i++)
    if(!viz[i]) {
        nr ++;
        bfs(i);
    }
    printf("%d", nr);
    return 0;
}