export {};

function dfs(now: number, link: number[][], visited: boolean[]): boolean[]{
    if(!visited[now]) visited[now] = true;
    for(let v of link[now]){
        if(!visited[v]) dfs(v, link, visited);
    }
    return visited;
}

const input: string[] = require("fs").readFileSync(0, "utf8").toString().trim().split('\n');
const [N, M] = input[0].split(' ').map(Number);
let visited: boolean[] = new Array(N+1).fill(false);
let link: number[][] = Array.from({length: N+1}, () => []);
for(let i=1; i<=M; i++) {
    const [u,v] = input[i].split(' ').map(Number);
    link[u].push(v);
    link[v].push(u);
}

let ConnectedComponentCount = 0
for(let now = 1 ; now<=N; now++){
    if(!visited[now]){
        ConnectedComponentCount++;
        dfs(now, link, visited);
    }
}
console.log(ConnectedComponentCount);