#include <stdio.h>
#include <stack>
#include <vector>
#define NMAX 100002
using namespace std;
int n,m,i;
vector<int> v[NMAX];
int viz[NMAX];
int sol = 0;

void dfs(int nod)
{
    for(int vecin : v[nod])
    {
        if(viz[vecin] == 0)
        {
            viz[vecin] = 1;
            dfs(vecin);
        }
    }
}
int main()
{
    freopen("dfs.in","r", stdin);
    freopen("dfs.out", "w", stdout);
    scanf("%d %d", &n, &m);
    for( i=0;i<m;i++)
    {
        int x ,y;
        scanf("%d %d", &x, &y);
        v[x].push_back(y);
        v[y].push_back(x);
    }
    for(i=1;i<=n;i++)
    {
        if(viz[i] == 0)
        {
            viz[i] = 1;
            dfs(i);
            sol++;
        }
    }
    printf("%d", sol);
    return 0;
}