#include <cstdio>
#include <vector>

using namespace std;

typedef long long LL;
typedef vector<int> vi;
typedef vector< vi > vii;
typedef vector<string> vs;
typedef vector<double> vd;
typedef pair<int, int> ii;
#define PB push_back
#define SZ(v) v.size()
#define ALL(v) (v).begin(), (v).end()
#define FORIT(i,c) for (typeof((c).end()) i=(c).begin(); i!=(c).end(); ++i)
#define FOR(i,n) for (int i = 0; i<(n); ++i)
#define FORE(i,n) for (int i = 0; i<=(n); ++i)
#define FORI(i,n1,n2) for (int i = n1; i<(n2); ++i)
#define FORIE(i,n1,n2) for (int i = n1; i<=(n2); ++i)
#define FORV(i,v) for (unsigned int i = 0; i<SZ(v); ++i)

#define INF 0x3f3f3f3f
#define EPS 1e-9

#define NMAX 100000

int N,M;
vi G[NMAX];
bool viz[NMAX];

void dfs(int node)
{
    viz[node] = true;
    FORV(i, G[node])
    {
        if (!viz[G[node][i]])
            dfs(G[node][i]);
    }

}

int main()
{
    freopen("dfs.in", "r", stdin);
    freopen("dfs.out", "w", stdout);

    scanf("%d %d", &N, &M);

    FOR(i,M)
    {
        int x,y;
        scanf("%d %d", &x, &y);
        G[x].PB(y);
        G[y].PB(x);
    }

    int sol = 0;

    FOR(i,N)
        if (!viz[i])
        {
            ++sol;
            dfs(i);
        }


    printf("%d\n", sol);

    return 0;
}