#include <cstdio>
#include <vector>
#include <bitset>
#define Nmax 100005

#define DIM 3666013

using namespace std;

char buffer[DIM];
int poz = DIM - 1;

void Scanf(int &A){
    A = 0;
    while('0' > buffer[poz] || buffer[poz] > '9')
        if(++poz == DIM)
            fread(buffer,1,DIM,stdin),poz = 0;
    while('0' <= buffer[poz] && buffer[poz] <= '9')
    {
        A = A * 10 + buffer[poz] - 48;
        if(++poz == DIM)
            fread(buffer,1,DIM,stdin),poz = 0;
    }
}

bitset<Nmax> used;
vector<vector<int> > G;
int N,M,cc;

void Read()
{
    Scanf(N);
    Scanf(M);
    G.resize(N+1);
    int a,b;
    for(int i = 1; i<= M; ++i){
        Scanf(a),Scanf(b);
        G[a].push_back(b);
        G[b].push_back(a);
    }
}

void DFS(int k){
    used[k] = 1;
    for(vector<int>::iterator it = G[k].begin(); it != G[k].end(); ++it)
        if(!used[*it])
            DFS(*it);
}

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

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

    return 0;
}