#include <stdio.h>
#include <vector>
using namespace std;
const int nMax=100001;
vector<int>G[nMax];
vector<bool>viz(nMax,false);
void dfs(int start){
    viz[start]=true;
    for(auto j:G[start])
        if(viz[j]==false)
            dfs(j);
}
int main(){
    freopen("dfs.in","r",stdin);
    freopen("dfs.out","w",stdout);
    int n,m;
    scanf("%d %d",&n,&m);
    for(int i=1;i<=m;++i){
        int x,y;
        scanf("%d %d",&x,&y);
        G[x].push_back(y);
        G[y].push_back(x);
    }
    int cnt=0;
    for(int i=1;i<=n;++i)
        if(viz[i]==false){
            dfs(i);
            cnt++;
        }
    printf("%d",cnt);
    return 0;
}