inline int recalc(int x, int sbz) {
    for (; p[x] != -1 && !usd[p[x]]; x = p[x])
        sz[x] -= sbz;
    sz[x] -= sbz;
    return x;
}

void decompose(int x, int cpr) {
    int ct = find_centroid(x, sz[x]); usd[ct] = 1;
    for (int i = 0; i < g[ct].size(); i++) {
        int to = g[ct][i];
        if (usd[to]) continue;
        if (to == p[ct]) {
            to = getp(to, sz[ct]);
            decompose(to, ct);
            continue;
        }
        decompose(to, ct);
    }
}