#include <cstdio>
#include <vector>
#include <algorithm>
using namespace std;
const int NMAX=100000;
vector<int> G[NMAX+5];
int n;
vector<int> viz;
const int WHITE=0;
void DFS(int u,int cc){
    viz[u]=cc;
    for (unsigned int j=0;j<G[u].size();j++){
        int v=G[u][j];
        if (viz[v]==WHITE){
            DFS(v,cc);
        }
    }
}
int main()
{
    freopen("dfs.in","r",stdin);
    freopen("dfs.out","w",stdout);
    int n,m,u,v,cc=0;
    scanf("%d%d",&n,&m);
    for (int i=0;i<m;i++){
        scanf("%d%d",&u,&v);
        G[u].push_back(v); G[v].push_back(u);
    }
    viz.assign(n+1,WHITE);
    for (int i=0;i<n;i++){
        if (viz[i]==WHITE){
            cc++;
            DFS(i,cc);
        }
    }
    printf("%d",cc);
    return 0;
}