#include <cstdio>
#include <vector>

using namespace std;

#define FIN "dfs.in"
#define FOUT "dfs.out"

#define MAX 100001

int N, M, R;
int D[MAX];

vector <int> V[MAX];

void DFS(int X)
{
    int i;

    D[X] = 1;
    for (i = 0; i < V[X].size(); ++ i)
        if (!D[V[X][i]])
            DFS(V[X][i]);
}

int main()
{
    int i, x, y;

    freopen(FIN, "r", stdin);
    freopen(FOUT, "w", stdout);

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

    for (i = 1; i <= M; ++ i)
    {
        scanf("%d%d", &x, &y);

        V[x].push_back(y);
        V[y].push_back(x);
    }

    for (i = 1; i <= N; ++ i)
        if (!D[i])
            ++ R, DFS(i);

    printf("%d\n", R);
}