#include <bits/stdc++.h>
#define pb push_back
using namespace std;
const int NMAX = 100000 + 5;
int n,m,x,y,sol;
vector <int> g[NMAX];
bool sel[NMAX];
inline void dfs(int x)
{
    sel[x]=true;
    for (int i = 0; i<g[x].size(); ++i)
        if (!sel[g[x][i]])
            dfs(g[x][i]);
    return ;
}
int main()
{
    freopen("dfs.in","r",stdin);
    freopen("dfs.out","w",stdout);
    scanf("%d %d\n", &n, &m);
    for (int i = 1; i<=m; ++i)
    {
        scanf("%d %d\n", &x, &y);
        g[x].pb(y);
        g[y].pb(x);
    }
    for (int i = 1; i<=n; ++i)
        if (!sel[i])
        {
            sol++;
            dfs(i);
        }
    printf("%d", sol);
    return 0;
}