poj3417

#include<iostream>
#include<cstdio>
#include<queue>
#include<algorithm>
#include<cmath>
#include<ctime>
#include<set>
#include<map>
#include<stack>
#include<cstring>
#define inf 2147483647
#define ls rt<<1
#define rs rt<<1|1
#define lson ls,nl,mid,l,r
#define rson rs,mid+1,nr,l,r
#define N 100010
#define For(i,a,b) for(int i=a;i<=b;i++)
#define p(a) putchar(a)
#define g() getchar()

using namespace std;

int n,m,x,y,ans;
int s,f[N][21],deep[N];
int d[N];

struct node{
    int n;
    node *next;
}*e[N];

void in(int &x){
    int y=1;
    char c=g();x=0;
    while(c<‘0‘||c>‘9‘){
        if(c==‘-‘)y=-1;
        c=g();
    }
    while(c<=‘9‘&&c>=‘0‘){
        x=(x<<1)+(x<<3)+c-‘0‘;c=g();
    }
    x*=y;
}
void o(int x){
    if(x<0){
        p(‘-‘);
        x=-x;
    }
    if(x>9)o(x/10);
    p(x%10+‘0‘);
}

void push(int x,int y){
    node *p;
    p=new node();
    p->n=y;
    if(e[x]==0)
        e[x]=p;
    else{
        p->next=e[x]->next;
        e[x]->next=p;
    }
}

void build(int now){
    deep[now]=deep[f[now][0]]+1;
    for(int i=1;(1<<i)<=deep[now];i++)
        f[now][i]=f[f[now][i-1]][i-1];
    for(node *i=e[now];i;i=i->next){
        if(i->n!=f[now][0]){
            f[i->n][0]=now;
            build(i->n);
        }
    }
}

int lca(int x,int y){
    if(deep[x]<deep[y])
        swap(x,y);
    int c=deep[x]-deep[y];
    For(i,0,log2(c))
        if((1<<i)&c)
            x=f[x][i];
    if(x==y)
        return x;
    for(int i=log2(deep[x]);i>=0;i--)
        if(f[x][i]!=f[y][i]){
            x=f[x][i];
            y=f[y][i];
        }
    return f[x][0];
}

int dfs(int x,int fa){
    for(node *i=e[x];i;i=i->next)
        if(i->n!=fa)
            d[x]+=dfs(i->n,x);
    return d[x];
}

int main(){
    in(n);in(m);
    For(i,1,n-1){
        in(x);in(y);
        push(x,y);
        push(y,x);
    }
    f[1][0]=1;
    build(1);
    For(i,1,m){
        in(x);in(y);
        d[x]+=1;d[y]+=1;
        d[lca(x,y)]-=2;
    }
    d[1]=dfs(1,1);
    For(i,1,n)
        if(!d[i]&&i!=1)
            ans+=m;
        else
            if(d[i]==1)
                ans++;
    o(ans);
    return 0;
}