#include<stdio.h>
#define MAX 100001
int parent(int);
int left(int);
int right(int);
int main(){
  int n,A[MAX],i;
  scanf("%d",&n);
  for(i=1;i<=n;i++){
    scanf("%d",&A[i]);
  }
  for(i=1;i<=n;i++){
    printf("node %d: key = %d, ",i,A[i]);
    if(parent(i)>=1) printf("parent key = %d, ",A[parent(i)]);
    if(left(i)<=n)printf("left key = %d, ",A[left(i)]);
    if(right(i)<=n)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;
}
  

