#include <bits/stdc++.h>
#define N 100001

using namespace std;

vector<int> v[N];

bool viz[N];

void dfs(int k){
    int q;
    viz[k]=true;
    for(int i=0;i<v[k].size();i++){
        q=v[k][i];
        if(viz[q]==false)
            dfs(q);
    }
}

int main()
{
    int n,m,a,b,s=0;
    FILE*fi,*fo;
    fi=fopen("dfs.in","r");
    fo=fopen("dfs.out","w");
    fscanf(fi,"%d%d",&n,&m);
    for(int i=0;i<m;i++){
        fscanf(fi,"%d%d",&a,&b);
        v[a].push_back(b);
        v[b].push_back(a);
    }
    for(int i=1;i<=n;i++){
        if(viz[i]==false)
        {
            dfs(i);
            s++;
        }
    }
    fprintf(fo,"%d",s);
    fclose(fi);
    fclose(fo);
    return 0;
}