#include <bits/stdc++.h>
using namespace std;
ifstream fin("dfs.in");
ofstream fout("dfs.out");

#define MAXN 100005
#define pb push_back
vector<int> G[MAXN];
bool used[MAXN];
int n,m,cc;

void dfs(int node){
    used[node] = 1;
    for(auto p : G[node])
        if(!used[p])
            dfs(p);
}

void solve(){
    int i;
    for(i=1; i<=n; i++){
        if(!used[i]){
            ++cc;
            dfs(i);
        }
    }
}

int main()
{
    fin>>n>>m;
    int x,y;
    while(m--){
        fin>>x>>y;
        G[x].pb(y);
        G[y].pb(x);
    }
    solve();
    fout<<cc;
    return 0;
}