#include<cstdio>
#include<vector>
#include<algorithm>;
using namespace std;
const int NMAX=100000;
int cc;
vector<int>viz;
vector<int>g[NMAX+5];
void dfs(int x)
{
    viz[x]=cc;
    for(int i=0;i<(int)g[x].size();++i)
    {
        int v=g[x][i];
        if(!viz[v])
            dfs(v);
    }
}

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