#include<cstdio>
#include<vector>
using namespace std;
FILE*in=fopen("dfs.in","r");
FILE*out=fopen("dfs.out","w");
const int NMAX=100007;
int n,m,i,j,x,y,ct;
vector<int> adj[NMAX];
bool b[NMAX];
void dfs(int nod)
{
    for(auto t:adj[nod])
    {
        if(b[t]==1)
        {
            continue;
        }
        b[t]=1;
        dfs(t);
    }
}
int main()
{
    fscanf(in,"%d%d",&n,&m);
    for(i=1;i<=m;i++)
    {
        fscanf(in,"%d%d",&x,&y);
        adj[x].push_back(y);
        adj[y].push_back(x);
    }
    for(i=1;i<=n;i++)
    {
        if(b[i]==0)
        {
            b[i]=1;
            dfs(i);
            ct++;
        }
    }
    fprintf(out,"%d",ct);
}