#include <stdio.h>
#include <vector>

int n, m;
std::vector<int> v[50001];
int lg, c=0;
bool viz[50001]={0};

void dfs( int x )
{
    int i, _lg;
    viz[x] = 1;
    _lg=v[x].size();
    for (i=0; i<_lg; i++)
        if (viz[v[x][i]]==0)
            dfs(v[x][i]);

    //sol[++lg] = x;
}

int main()
{

    int i, x, y;

    freopen( "dfs.in", "rt", stdin );
    freopen( "dfs.out", "wt", stdout );

    scanf( "%d %d", &n, &m );
    for (i=0; 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]==0)
            c++, dfs(i);


    printf("%d\n", c);
}