#include <stdio.h>
#include <vector>


using namespace std;
const int NMAX = 100005;

vector<int> matrice [NMAX];
int viz[NMAX] = {0};
int n,m,ct;

void DFS(int a)
{
    int i;
    viz[a]=1;
    for(i=0;i< matrice[a].size();++i)
    {
        if(viz[matrice[a][i]] == 0){
            DFS(matrice[a][i]);
        }
    }
}

int main()
{
    int i,x,y;
    freopen("dfs.in","r",stdin);
    freopen("dfs.out","w",stdout);
    scanf("%d%d\n",&n, &m);
    for(i = 0;i < m; ++i)
    {
        scanf("%d%d\n",&x,&y);
        matrice[x].push_back(y);
        matrice[y].push_back(x);
    }
    for(i=1;i<= n; ++i)
    {
        if(!viz[i])
        {
            ct++;
            DFS(i);
        }
    }
    printf("%d\n", ct);
    return 0;
}