#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 n){
  return n/2;
}

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

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

