#include <cstdio>
#include <vector>
#include <algorithm>
using namespace std;

#define NMAX 100010
vector<int> V[NMAX];
int N, M, K;
bool viz[NMAX];

void citire() {
    scanf("%d %d\n", &N, &M);
    for (int x, y;M;--M) {
        scanf("%d %d\n", &x, &y);
        V[x].push_back(y);
        V[y].push_back(x);
    }
}

void dfs(int n) {
    viz[n] = true;
    for (int i=0, e = V[n].size(); i<e; ++i) {
        if (!viz[V[n][i]])
            dfs(V[n][i]);
    }
}

int main () {

    freopen("dfs.in","rt",stdin);
    freopen("dfs.out","wt",stdout);

    K = 0;
    citire();
    for (int i=1; i<=N; ++i) {
        if (!viz[i]) {
            K++;
            dfs(i);
        }
    }
    printf("%d\n", K);

    return 0;
}