// #pragma GCC optimize("Ofast")
// #pragma GCC target("avx,avx2,fma")
// #pragma GCC optimization ("unroll-loops")

#include <bits/stdc++.h>

using namespace std;

void __print(int x) {cerr << x;}
void __print(long x) {cerr << x;}
void __print(long long x) {cerr << x;}
void __print(unsigned x) {cerr << x;}
void __print(unsigned long x) {cerr << x;}
void __print(unsigned long long x) {cerr << x;}
void __print(float x) {cerr << x;}
void __print(double x) {cerr << x;}
void __print(long double x) {cerr << x;}
void __print(char x) {cerr << '\'' << x << '\'';}
void __print(const char *x) {cerr << '\"' << x << '\"';}
void __print(const string &x) {cerr << '\"' << x << '\"';}
void __print(bool x) {cerr << (x ? "true" : "false");}

template<typename T, typename V>
void __print(const pair<T, V> &x) {cerr << '{'; __print(x.first); cerr << ','; __print(x.second); cerr << '}';}
template<typename T>
void __print(const T &x) {int f = 0; cerr << '{'; for (auto &i: x) cerr << (f++ ? "," : ""), __print(i); cerr << "}";}
void _print() {cerr << "]\n";}
template <typename T, typename... V>
void _print(T t, V... v) {__print(t); if (sizeof...(v)) cerr << ", "; _print(v...);}
#ifndef ONLINE_JUDGE
#define debug(x...) cerr << "[" << #x << "] = ["; _print(x)
#else
#define debug(x...)
#endif
#define ll long long int

const int nax=1e5+10;

vector<bool> inc(nax,false);
vector<vector<int>> g(nax);

void dfs(int node,int par){
    inc[node]=true;
    for(auto v:g[node]){
        if(!inc[v]){
            dfs(v,node);
        }
    }
}

int main(){
    ifstream in("dfs.in");
    ofstream out("dfs.out");
    int n,m;
    in>>n>>m;
    int u,v;
    for(int i=0;i<m;i++){
        in>>u>>v;
        g[u].push_back(v);
        g[v].push_back(u);
    }
    int cnt=0;
    for(int i=1;i<=n;i++){
        if(!inc[i]){
            dfs(i,-1);
            cnt++;
        }
    }
    out<<cnt<<"\n";
    return 0;        
}