code:
#include <bits/stdc++.h>
using namespace std;
const int N = 1e5 + 10;
int n, m;
int f[N];

int find(int x){
    if(x != f[x])f[x] = find(f[x]);
    return f[x];
}

void merge(int a, int b){
    a = find(a), b = find(b);
    f[a] = b;
}

int main()
{
    ios::sync_with_stdio(false);
    cin.tie(0);
    cout.tie(0);

    cin >> n >> m;
    for(int i = 1;i <= n;i++)f[i] = i;
    for(int i = 1;i <= m;i++){
        int a, b;
        cin >> a >> b;
        merge(a, b);
    }

    int ans = 0;
    for(int i = 1;i <= n;i++)if(f[i] == i)ans++;
    cout << ans;

    return 0;
}