let cnt = 0;
function Dfs(visited, tree, i) {
    if (visited[i]) {
        return;
    }
    
    visited[i] = true;
    ++cnt
    if (tree[i]) {
        for (let v of tree[i]) {
            Dfs(visited, tree, v);
        }
    }
}

/*
 * Complete the 'journeyToMoon' function below.
 *
 * The function is expected to return an INTEGER.
 * The function accepts following parameters:
 *  1. INTEGER n
 *  2. 2D_INTEGER_ARRAY astronaut
 */

function journeyToMoon(n, astronaut) {
    // Write your code here
    let tree = {};
    for (const [a1, a2] of astronaut) {
        tree[a1] = tree[a1] ?? new Set();
        tree[a2] = tree[a2] ?? new Set();
        tree[a1].add(a2);
        tree[a2].add(a1);
    }
    let a = [];
    let ans = 0;

    for (let i=0;i<n;++i) {
        if (!visited[i]) {
            Dfs(visited, tree, i);
            a.push(cnt);
            cnt = 0;
        }
    }
    
    for (let i=0;i<a.length;++i) {
        for (let j=i+1;j<a.length;++j) {
            ans += a[i] * a[j];
        }
    }
    return ans;
}