#include <cstdio>
#include <vector>
#include <queue>

using namespace std;

vector <int> g[100005];
bool viz[100005];
int n, m, s;

void dfs(int i)
{
    for(auto &v:g[i])
    {
        if(viz[v]==0)
        {
            viz[v]=1;
            dfs(v);
        }
    }
}

int main()
{
    freopen("dfs.in", "r", stdin);
    freopen("dfs.out", "w", stdout);

    scanf("%d %d", &n, &m);

    for(int i=0; i<m; i++)
    {
        int x, y;
        scanf("%d %d", &x, &y);
        g[x].push_back(y);
        g[y].push_back(x);
    }
    int nr=0;
    for(int i=1; i<=n; i++)
    {
        if(viz[i]==0)
        {
            viz[i]=1;
            dfs(i);
            nr++;
        }
    }
    printf("%d", nr);

    return 0;
}