#include<stdio.h>
#define MAX 100000

int parent(int);
int left(int);
int right(int);


int main(){
int H,i,A[MAX+1];

scanf("%d", &H);

 for ( i = 1; i <= H; i++ ){
   scanf("%d",&A[i]);
 }

 for ( i = 1; i <= H; i++ ){
   printf("node %d: key = %d, ",i,A[i]);
   if (parent(i)>=1){
     printf("parent key = %d, ",A[parent(i)]);
   } 
   if (left(i)<=H){
     printf("left key = %d, ",A[left(i)]);
   }
   if (right(i)<=H){
     printf("right key = %d,",A[right(i)]);
   }
   printf("\n");
 }
  

 return 0;
}

int parent(int i){
  return i/2;
}

int left(int i){
  return 2*i;
}

int right(int i){
  return 2*i+1;
}