#include<stdio.h>
#define MAX 250
int le(int);int ri(int);int par(int);
int main(){
  int H,A[MAX+1],i;
  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(i>1)printf("parent key = %d, ",A[par(i)]);
    if(le(i)<=H)printf("left key = %d, ",A[le(i)]);
    if(ri(i)<=H)printf("right key = %d, ",A[ri(i)]);
    printf("\n");
  }
  
  return 0;
}

int par(int i){
  return i/2;
}

int le(int i){
  return 2*i;
}

int ri(int i){
  return 2*i+1;
}

