#include <cstdio>
#include <vector>

#define NMAX 100010
using namespace std;
vector<int> G[NMAX];
int N,M,x,y,i,nrc;
bool vizitat[NMAX];

void dfs(int nod)
{
    vizitat[nod]=true;
    for (vector<int> :: iterator itt = G[nod].begin(); itt != G[nod].end(); ++itt)
        if (vizitat[*itt]==false)
            dfs(*itt);
}

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

    scanf("%d %d", &N, &M);
    for (i=1; i<=M; i++)
    {
        scanf("%d %d", &x, &y);
        G[x].push_back(y);
        G[y].push_back(x);
    }

    for (i=1; i<=N; i++)
        if (vizitat[i]==false)
        {
            dfs(i);
            nrc++;
        }

    printf("%d", nrc);

    return 0;
}