#include<bits/stdc++.h>
#pragma GCC optimize(2)
using namespace std;

long long ans = 0;
int N, S, cid = 0;
int u, v;
vector<int> E[100005];
priority_queue<int, vector<int>, greater<int> > q;
int fa[100005];

void erg(int u){
	for (auto && v : E[u]){
		if (v == fa[u]) continue;
		fa[v] = u;
		erg(v);
	}
}

int main(){
#ifndef ONLINE_JUDGE
	freopen("../data.in", "r", stdin);
	freopen("../data.out", "w", stdout);
#endif

	scanf("%d %d", &N, &S);
	for (int i = 1; i < N; i ++){
		scanf("%d %d", &u, &v);
		E[u].push_back(v);
		E[v].push_back(u);
	}
	erg(S);
	q.push(S);
	while (!q.empty()){
		int u = q.top();
		q.pop();
		cid ++;
		ans += 1LL * u * cid;
		for (auto && v : E[u]){
			if (v == fa[u]) continue;
			q.push(v);
		}
	}
	printf("%lld\n", ans);

	return 0;
}