#include<stdio.h>
#define Max 10001
int parent(int);
int left(int);
int right(int);
int main(){
  int heap,i,A[Max];
  scanf("%d",&heap);
  for(i=1;i<=heap;i++)
    scanf("%d",&A[i]);
  for(i=1;i<=heap;i++){
    printf("node: %d: key = %d,",i,A[i]);
    if(parent(i)>=1)printf("parent key = %d, ",A[parent(i)]);
    if(left(i)<=heap)printf("left key = %d, ",A[left(i)]);
    if(right(i)<=heap)printf("right key = %d, ",A[right(i)]);
    printf("\n");
  }
  return 0;
}
int parent(int x){
  return x/2;
}
int left(int x){
  return 2*x;
}
int right(int x){
  return 2*x+1;
}