#include <bits/stdc++.h>
#define oo 1<<30

using namespace std;
int n, m, i, x, y, sol;
vector<int>v[100005];
bitset<100005>viz;
void df(int nod)
{
    if(viz[nod])
        return;
    for(auto it:v[nod])
        df(it);
}
int main()
{
    freopen("dfs.in", "r", stdin);
    freopen("dfs.out", "w", stdout);
    scanf("%d%d", &n, &m);
    for(; m; m--)
    {
        scanf("%d%d", &x, &y);
        v[x].push_back(y);
        v[y].push_back(x);
    }
    for(i = 1; i <= n; i++)
        if(!viz[i])
        {
            sol++;
            df(i);
        }
    printf("%d",sol);
    return 0;
}