#include <cstdio>
#include <vector>

using namespace std;

#define maxN 100010
#define PB push_back

vector <int> list[maxN];
bool mark[maxN];


void DFS (int nod)
{
    mark[nod] = true;
    for (int i = 0; i < list[nod].size(); ++ i)
    {
        if (mark[list[nod][i]]) continue;
        DFS (list[nod][i]);
    }
}


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

    int N, M, sol = 0;
    scanf ("%d %d", &N, &M);

    while (M --)
    {
        int x, y;
        scanf ("%d %d", &x, &y);
        list[x].PB (y);
        list[y].PB (x);
    }

    for (int i = 1; i <= N; ++ i)
    {
        if (mark[i]) continue;
        DFS (i);
        ++ sol;
    }

    printf ("%d", sol);

    return 0;
}