#include<cstdio>
#include<vector>
using namespace std;
vector<int> a[100001];
int viz[100001];
void dfs(int x){
    viz[x]=1;
    int i;
    for(i=0;i<a[x].size();i++)
        if (viz[a[x][i]]==0) dfs(a[x][i]);
}
int main(){
    freopen ("dfs.in","r",stdin);
    freopen ("dfs.out","w",stdout);
    int n,m,i,x,y;
    scanf ("%d%d",&n,&m);
    for(i=1;i<=m;i++){
        scanf ("%d%d",&x,&y);
        a[x].push_back(y);
        a[y].push_back(x);
    }
    x=0;
    for(i=1;i<=n;i++)
        if (viz[i]==0){
            x++;
            dfs(i);
        }
    printf ("%d",x);
    return 0;
}