#include <bits/stdc++.h>

using namespace std;
ifstream in("listavecini.in");
ofstream out("listavecini.out");
#define NMAX 100001
vector <int>v[NMAX];
int cnt;
bool seen[NMAX];
void dfs(int i){
    seen[i]=1;
    for(int j=0;j<v[i].size();j++){
        if(!seen[v[i][j]])
            dfs(v[i][j]);
    }
}
int main()
{
    int n,m;
    in>>n>>m;
    int x,y;
    while(in>>x>>y){
        v[x].push_back(y);
        v[y].push_back(x);
    }
    for(int i=1;i<=n;i++){
        if(!seen[i]){
            dfs(i);
            cnt++;
        }
    }
  out<<cnt;
    return 0;
}