#include <bits/stdc++.h>
#define ll long long

using namespace std;
ifstream fin("dfs.in");
ofstream fout("dfs.out");
vector<int>G[100001];
int n,m,f[100001];
void dfs(int nod){
    f[nod]=1;
    for(auto x : G[nod]){
        int vecin = x;
        if(f[vecin]==0){
            dfs(vecin);
        }
    }
}
int main(){
    fin>>n>>m;
    while(m--){
        int x,y; fin>>x>>y;
        G[x].push_back(y);
        G[y].push_back(x);
        }
    int cnt = 0;
    for(int i = 1; i <=n; i++){
        if(f[i]==0){
            cnt++;
            dfs(i);
        }
    }
    fout<<cnt;
    return 0;
}