#include<iostream>
#include<vector>
using namespace std;

#define NMAX 100001

int n,m;
bool b[NMAX];
vector<int>g[NMAX];
void dfs(int i){
    b[i]=true;
    for(auto it:g[i]){
        if(b[it])continue;
        dfs(it);
    }
}
signed main(){
#ifndef LOCAL
    ios::sync_with_stdio(false);
    cin.tie(nullptr);
    cout.tie(nullptr);
#endif // LOCAL
    freopen("dfs.in","r",stdin);
    freopen("dfs.out","w",stdout);
    cin>>n>>m;
    for(int i=1;i<=m;++i){
        int x,y;
        cin>>x>>y;
        g[x].push_back(y);
        g[y].push_back(x);
    }
    int ans=0;
    for(int i=1;i<=n;++i){
        if(b[i])continue;
        dfs(i);
        ++ans;
    }
    cout<<ans;
    return 0;
}