#include <cstdio>
#include <vector>
#include <queue>
#define maxn 100005

using namespace std;
FILE *f=fopen("dfs.in","r");
FILE *g=fopen("dfs.out","w");
vector <int> G[maxn],viz(maxn,0);
queue <int> Q;
int n,m,x,y,nrc;

void dfs(int nod){
    viz[nod]=1;
    for(int i=0;i<G[nod].size();i++){
        if(viz[G[nod][i]]==0)
            dfs(G[nod][i]);
    }
}
int main()
{
    fscanf(f,"%d%d",&n,&m);
    for(int i=1;i<=m;i++){
        fscanf(f,"%d%d",&x,&y);
        G[x].push_back(y);
        G[y].push_back(x);
    }
    for(int i=1;i<=n;i++)
        if(viz[i]==0)
            dfs(i),nrc++;

    fprintf(g,"%d",nrc);
    return 0;
}