#include <cstdio>
#include <vector>
#include <bitset>
#define MAX_N 100000

using namespace std;

int M, N, cnt;
vector <int> V[MAX_N];
bitset <MAX_N> viz;

void read()
{
    int x,y;
    scanf("%d %d",&N,&M);

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

void DFS(int nod)
{
    viz[nod] = 1;
    for(int i = 0; i < V[nod].size(); ++i)
        if(!viz[V[nod][i]])
            DFS(V[nod][i]);
}

int main()
{
    freopen("dfs.in","rt",stdin);
    freopen("dfs.out","wt",stdout);

    read();
    for(int i = 1; i <= N; ++i)
        if(!viz[i])
        {
            cnt++;
            DFS(i);
        }
    printf("%d\n",cnt);
}