#include <cstdio>
#include <vector>

using namespace std;
const int NMAX=100000;
vector <int> G[NMAX+5];
int viz[NMAX+5];

void DFS(int u, int cc)
{
    int v;
    viz[u]=cc;
    for(int j=0; j<G[u].size(); j++)
    {
        v=G[u][j];
        if (!viz[v])
            DFS(v, cc);
    }
}

int main()
{
    freopen("dfs.in", "r", stdin);
    freopen("dfs.out", "w", stdout);
    int n, m, u, v, cc, i;
    scanf("%d%d", &n, &m);
    for(i=1; i<=m; i++)
    {
        scanf("%d%d", &u, &v);
        G[u].push_back(v);
        G[v].push_back(u);
    }
    cc=0;
    for(i=1; i<=n; i++)
    {
        if (!viz[i])
        {
            cc++;
            DFS(i, cc);
        }
    }
    printf("%d\n", cc);
    return 0;
}