#include <iostream>
#include <cstdio>
#include <vector>

using namespace std;

#define maxN 100005

vector <int> muchii[maxN];
bool viz[maxN];

void dfs(int root) {
    viz[root] = true;

    for(unsigned int i = 0; i < muchii[root].size(); ++i) {
        int node = muchii[root][i];

        if(viz[node])
            continue;

        dfs(node);
    }
}

int main()
{
    freopen("dfs.in", "r", stdin);
    freopen("dfs.out", "w", stdout);

    int N, M, x, y;

    scanf("%d %d", &N, &M);

    for(int i = 0; i < M; ++i) {
        scanf("%d %d", &x, &y);
        muchii[x].push_back(y);
        muchii[y].push_back(x);
    }

    int compConex = 0;

    for(int i = 1; i <= N; ++i) {
        if(viz[i])
            continue;

        dfs(i);
        compConex++;
    }

    printf("%d", compConex);

    return 0;
}