#include <bits/stdc++.h>
using namespace std;

const int NMAX = 1e5+5;

bool        f[NMAX];
vector<int> g[NMAX];

void dfs(int u) {
    f[u] = 1;
    for(int i=0; i<g[u].size(); ++i)
        if(!f[g[u][i]])
            dfs(g[u][i]);
}

int main(void) {
    FILE *fi = fopen("dfs.in","r");
    FILE *fo = fopen("dfs.out","w");
    int n, m, a, b, ans;

    ans = 0;

    fscanf(fi,"%d%d",&n,&m);
    while(m--) {
        fscanf(fi,"%d%d",&a,&b);
        g[a].push_back(b);
        g[b].push_back(a);
    }
    for(int i=1; i<=n; ++i) {
        if(!f[i]) {
            dfs(i);
            ++ans;
        }
    }

    fprintf(fo,"%d\n",ans);

    fclose(fi);
    fclose(fo);
    return 0;
}