#include <iostream>
#define Nmax 100005
#include <vector>
#include <stdio.h>
using namespace std;
vector<int>G[Nmax];
int n,m,con;
bool viz[Nmax];
void read()
{
    int x,y;
    scanf("%d%d",&n,&m);
    for(int i=1;i<=m;i++)
    {
        scanf("%d%d",&x,&y);
        G[x].push_back(y);
        G[y].push_back(x);
    }

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

        if(!viz[G[x][i]])
        DFS(G[x][i]);
}
void solv()
{
    for(int i=1;i<=n;i++)
        if(!viz[i])
    {
        DFS(i);
        con++;
    }
}
int main()
{
    freopen("dfs.in","r",stdin);
    freopen("dfs.out","w",stdout);
    read();
    solv();
    printf("%d",con);

}