#include <iostream>

#include <stdio.h>

using namespace std;

int main()

{

int n;

int stud[10000];

int i;

int a, b;

int cur;

int step;

scanf(" %d",&n);

for(i=0; i<n; i++){

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

a--;

b--;

stud[a] = b; //SINCE ONE FRIEND IS ONLY ASSIGNED TO ONE OTHER FRIEND, WE CAN STORE THIS INFORMATION USING THE INDEX OF AN ARRAY AND ITS VALUE

}

while(1){

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

if(a==0){

return 0;

}

a--;

b--;

cur = a; //WE START FROM THE FIRST INDEX

step = 0;

while(1){

cur = stud[cur]; //WE FOLLOW THE CIRCLE OF FRIENDS BY FOLLOWING THE VALUE OF THE INDICES

if(cur == b){ //IF THE CURRENT INDEX IS EQUAL TO THE OBJECTIVE INDEX, WE'VE REACHED OUR GOAL

printf("Yes %d\n", step);

break;

}

if(cur == a){ //IF THE CURRENT INDEX RETURNS TO THE FIRST INDEX WITHOUT REACHING THE OBJECTIVE INDEX, THEY ARE NOT IN THE SAME CIRCLE OF FRIENDS

printf("No\n");

break;

}

step++; //SINCE THE STEP COUNTER IS ALWAYS THE NUMBER OF FRIENDS IN BETWEEN TWO FRIENDS, WE START AT 0 AND INCREASE AFTER CHECKING

}

}

return 0;

}