#include <stdio.h>
 
int A[100001],B[100001];
int L[100001],R[100001];
int parent[100001];
 
int main() {
 
	int n,a,b,c,d,sum=2;
	scanf("%d",&n);
	int i;for(i=1;i<=n;i++){
		scanf("%d %d",&a,&b);
		if(a) L[i]=sum++; 
		if(b) R[i]=sum++; 
		parent[L[i]]=i;
		parent[R[i]]=i;
	}
	int cnt=0,last;
	scanf("%d %d",&a,&b);
	while(a>=1){
		A[a]=cnt;
		a=parent[a];
		cnt++;
	}
	cnt=0;
	while(b>=1){
		B[b]=cnt;
		if(A[b]==B[b]&&B[b]) {
			last=A[b]+B[b];
			break;
		}
		b=parent[b];
		cnt++;
	}
 
	for(i=1;i<=b;i++)
		printf("%d %d\n",A[i],B[i]);
 
	return 0;
}
 

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

OAoxIDEgMCAwIDEgMSAxIDAgMSAxIDAgMCAwIDAgMCAwCjEgMg==

8
1 1 0 0 1 1 1 0 1 1 0 0 0 0 0 0
1 2