#include <cstdio>
#define Nmax 100005
#include <vector>

using namespace std;

vector <int> G[Nmax];

int vizitat[Nmax];

FILE * f=fopen("dfs.in","r");
FILE * g=fopen("dfs.out","w");
int n,m,cnt;

void dfs(int i)
{
    vizitat[i]=1;
    for(auto it: G[i])
        if(!vizitat[it])
        dfs(it);
}

int main()
{
    int i;
    fscanf(f,"%d%d",&n,&m);
    for(i=1; i<=m; i++)
    {
        int x,y;
        fscanf(f,"%d%d",&x,&y);
        G[x].push_back(y);
        G[y].push_back(x);
    }
    for(i=1; i<=n; i++)
        if(!vizitat[i])
        {
            cnt++;
            dfs(i);
        }
    fprintf(g,"%d",cnt);
    return 0;
}