#include <cstdio>
#include <vector>

#define dim 100010
using namespace std;
vector <int> v[dim];
int n, m, i, x, y, nr;
bool viz[dim];

void srch(int nod)
{
    if(v[nod].size())
    for(int j=0;j<=v[nod].size()-1;j++)
        if(!viz[v[nod][j]])
        {
            viz[v[nod][j]]=1;
            srch(v[nod][j]);
        }
}

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