#include <iostream>
#include <deque>
#include <vector>
#include <cstring>
#include <bitset>
#include <algorithm>
#define INF 1000010
#define ll long long
using namespace std;

int N, M, i, x, y, sol, viz[100010];
vector<int> V[100010];

void DFS(int X)
{
    viz[X] = 1;
    for(vector<int>::iterator it = V[X].begin(); it != V[X].end(); it++)
        if(!viz[*it])
            DFS(*it);
}


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