if(u==v&&v==x) printf("%d\n",n);
        else if(!pd(u,v,x)) printf("0\n");
        else
        {
            while(d[u]>d[x]+1) u=fa[u][lg[d[u]-d[x]-1]];
            while(d[v]>d[x]+1) v=fa[v][lg[d[v]-d[x]-1]];
            if(fa[u][0]==x&&fa[v][0]==x) printf("%d\n",n-s(x,u)-s(x,v));
            else if(fa[u][0]==x) printf("%d\n",sum[x]-s(x,u));
            else if(fa[v][0]==x) printf("%d\n",sum[x]-s(x,v));
        }