#include <stdio.h>
#include <stdlib.h>
int parent(int);
int left(int);
int right(int);

int main(){
  int h,i;
  int *A;
  scanf("%d",&h);
  A=(int *)malloc(h * sizeof(int));
  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(i!=1) printf("parent key = %d, ",A[parent(i)]);
    if(0<left(i) && left(i)<=h) printf("left key = %d, ",A[left(i)]);
    if(0<right(i) && right(i)<=h) printf("right key = %d, ",A[right(i)]);
    printf("\n");
  }
  free(A);
  return 0;
}

  int parent(int i){
    if(i%2==0) return i/2;
    else return (i-1)/2;
  }
  int left(int i){
    return 2*i;
  }
  int right(int i){
    return 2*i+1;
  }