#include <cstdio>
#include <vector>
#include <algorithm>
using namespace std;
vector<int>g[100005];
bool viz[100005];
void dfs(int nod)
{
    int i;
    viz[nod]=1;
    for(i=0; i<g[nod].size(); i++)
        if(!viz[g[nod][i]])
            dfs(g[nod][i]);
}
int main()
{  freopen("dfs.in", "r",stdin);
    freopen("dfs.out", "w",stdout);
    int n,m,i,u,v,nr=0;
    scanf("%d%d", &n, &m);
    for(i=1; i<=m; i++){
        scanf("%d%d", &u, &v);
        g[u].push_back(v);
        g[v].push_back(u);
    }
    for(i=1; i<=n; i++)
        if(viz[i]==0){
            nr++;
            dfs(i);
        }
    printf("%d", nr);
    return 0;
}