#include<cstdio>
#include<vector>
using namespace std;

int viz[100001],i,n,m,x,y,nr;
vector <int> G[100001];

void dfs(int nod)
{
    int i;
    if(viz[nod])
        return;
    viz[nod]=nr;
    for(i=0;i<G[nod].size();i++)
        dfs(G[nod][i]);
}

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(viz[i]==0)
        {
            nr++;
            dfs(i);
        }
    printf("%d\n",nr);

    return 0;
}