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

using namespace std;

vector <int> graph[100005];
//queue <int> q;

int n, m, x, y, nr;
//int s,;
bool viz[100005];

void filll(int x)
{
    for(auto &v:graph[x])
    {
        if(viz[v] == 0)
        {
            viz[v]=1;
            filll(v);
        }
    }
}

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