--------传送门--------

#include <bits/stdc++.h>
#define x first
#define y second
using namespace std;
typedef long long ll;
typedef pair<int, int> PII;

const int N = 1e5 + 10;
vector<int> e[N];
int n, m;
int dep[N];
int ans;
int fa[N][20];
int d[N];

void bfs()
{
    memset(dep, 0x3f, sizeof dep);
    dep[0] = 0, dep[1] = 1;
    queue<int> q;
    q.push(1);

    while (!q.empty())
    {
        auto t = q.front(); q.pop();
        for (int i = 0; i < e[t].size(); i ++)
        {
            int j = e[t][i];
            if (dep[j] > dep[t] + 1)
            {
                dep[j] = dep[t] + 1;
                q.push(j);
                fa[j][0] = t;
                for (int k = 1; k <= 17; k ++)
                    fa[j][k] = fa[fa[j][k - 1]][k - 1];
            }
        }
    }
}

int lca(int a, int b)
{
    if (dep[a] < dep[b]) swap(a, b);

    for (int i = 17; i >= 0; i --)
        if (dep[fa[a][i]] >= dep[b])
            a = fa[a][i];

    if (a == b) return a;
    for (int i = 17; i >= 0; i --)
        if (fa[a][i] != fa[b][i])
        {
            a = fa[a][i];
            b = fa[b][i];
        }

    return fa[a][0];
}

int dfs(int u, int fa)
{
    int res = d[u];
    for (int i = 0; i < e[u].size(); i ++)
    {
        int j = e[u][i];
        if (j == fa) continue;

        int s = dfs(j, u);

        if (s == 0) ans += m;
        else if (s == 1) ans ++;

        res += s;
    }
    return res;
}

int main()
{
    ios::sync_with_stdio(false), cin.tie(0);

    cin >> n >> m;
    for (int i = 1; i < n; i ++)
    {
        int x, y;
        cin >> x >> y;
        e[x].push_back(y);
        e[y].push_back(x);
    }

    bfs();

    for (int i = 0; i < m; i ++)
    {
        int a, b;
        cin >> a >> b;
        int LCA = lca(a, b);
        d[a] ++, d[b] ++, d[LCA] -= 2;
    }

    dfs(1, -1);
    cout << ans << "\n";

    return 0;
}