#include <iostream>
#include <fstream>
#define NMAX 105

using namespace std;

ifstream fin("dfs.in");
ofstream fout("dfs.out");

bool adj[NMAX][NMAX], visited[NMAX];
int n, m, x, y;

void read()
{
    fin >> n >> m;

    for (int i = 0; i < m; ++ i) {
        fin >> x >> y;
        adj[x][y] = adj[y][x] = 1;
    }
}

void dfs(int node)
{
    visited[node] = 1;

    for (int i = 1; i <= n; ++ i) {
        if (!visited[i] && adj[node][i] == 1) {
            dfs(i);
        }
    }
}

int main()
{
    read();
    int k=0;
    for(int i=1;i<=n;i++)
        if(!visited[i]){
            dfs(i);
            k++;
        }
    fout << k;
    return 0;
}