#include <cstdio>
#include <vector>

using namespace std;

#define FIN "dfs.in"
#define FOUT "dfs.out"
#define MAX_N 100015
#define PB push_back
#define SZ(A) (int)((A).size())

int N, M;
vector<int> G[MAX_N];
bool viz[MAX_N];

void read() {
    scanf("%d %d", &N, &M);
    for (int i = 1; i <= M; ++i) {
        int a, b;
        scanf("%d %d", &a, &b);
        G[a].PB(b);
        G[b].PB(a);
    }
}

void DFS(int nod) {
    viz[nod] = true;
    for (int i = 0; i < SZ(G[nod]); ++i)
        if (!viz[G[nod][i]])
            DFS(G[nod][i]);
}

void solve() {
    int comp = 0;
    for (int i = 1; i <= N; ++i)
        if (!viz[i]) {
            DFS(i);
            ++comp;
        }
    printf("%d\n", comp);
}

int main() {
    freopen(FIN, "r", stdin);
    freopen(FOUT, "w", stdout);
    read();
    solve();
    return 0;
}