#include<cstring>

#include<cstdio>

#include<cstring>

using namespace std;

struct node

{

int data,rev,sum;

node *son[2],*pre;

bool judge();

bool isroot();

void pushdown();

void update();

void setson(node *child,int lr);

}lct[233];

int top,a,b;

node *getnew(int x)

{

node *now=lct+ ++top;

now->data=x;

now->pre=now->son[1]=now->son[0]=lct;

now->sum=0;

now->rev=0;

return now;

}

bool node::judge(){return pre->son[1]==this;}

bool node::isroot()

{

if(pre==lct)return true;

return !(pre->son[1]==this||pre->son[0]==this);

}

void node::pushdown()

{

if(this==lct||!rev)return;

swap(son[0],son[1]);

son[0]->rev^=1;

son[1]->rev^=1;

rev=0;

}

void node::update(){sum=son[1]->sum+son[0]->sum+data;}

void node::setson(node *child,int lr)

{

this->pushdown();

child->pre=this;

son[lr]=child;

this->update();

}

void rotate(node *now)

{

node *father=now->pre,*grandfa=father->pre;

if(!father->isroot()) grandfa->pushdown();

father->pushdown();now->pushdown();

int lr=now->judge();

father->setson(now->son[lr^1],lr);

if(father->isroot()) now->pre=grandfa;

else grandfa->setson(now,father->judge());

now->setson(father,lr^1);

father->update();now->update();

if(grandfa!=lct) grandfa->update();

}

void splay(node *now)

{

if(now->isroot())return;

for(;!now->isroot();rotate(now))

if(!now->pre->isroot())

now->judge()==now->pre->judge()?rotate(now->pre):rotate(now);

}

node *access(node *now)

{

node *last=lct;

for(;now!=lct;last=now,now=now->pre)

{

splay(now);

now->setson(last,1);

}

return last;

}

void changeroot(node *now)

{

access(now)->rev^=1;

splay(now);

}

void connect(node *x,node *y)

{

changeroot(x);

x->pre=y;

access(x);

}

void cut(node *x,node *y)

{

changeroot(x);

access(y);

splay(x);

x->pushdown();

x->son[1]=y->pre=lct;

x->update();

}

int query(node *x,node *y)

{

changeroot(x);

node *now=access(y);

return now->sum;

}

int main()

{

scanf("%d%d",&a,&b);

node *A=getnew(a);

node *B=getnew(b);

//连边 Link

connect(A,B);

//断边 Cut

cut(A,B);

//再连边orz Link again

connect(A,B);

printf("%d\n",query(A,B));

return 0;

}