#include<stdio.h>
#define MAX 100000

int p(int i){return i/2;}
int l(int i){return 2*i;}
int r(int i){return 2*i+1;}

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(p(i)>=1) printf("parent key = %d, ",A[p(i)]);
    if(l(i)<=H) printf("left key = %d, ",A[l(i)]);
    if(r(i)<=H) printf("right key = %d, ",A[r(i)]);
    printf("\n");
  }
  return 0;
}

  

