#include <bits/stdc++.h>
using namespace std;
int n,m,x,y,ap[100001],nr;

void date()
{
    freopen("dfs.in","r",stdin);
    freopen("dfs.out","w",stdout);
}
vector <int> G[100001];
void dfs(int x)
{
    ap[x]=1;
    for(int i=0;i<G[x].size();i++)
        if(ap[G[x][i]]==0)
            dfs(G[x][i]);

}
int main()
{
    date();
    scanf("%d%d",&n,&m);
    while(m--)
    {
        scanf("%d%d",&x,&y);
        G[x].push_back(y);
        G[y].push_back(x);
    }

    for(int i=1;i<=n;i++)
        if(ap[i]==0){
            nr++;
            dfs(i);
        }
    printf("%d\n",nr);

    return 0;
}