#include<stdio.h>

int main(){
  int n,i,Array[250],left,right;
  scanf("%d",&n);
  for(i=1;i<=n;i++){
    scanf("%d",&Array[i]);
  }
  for(i=1;i<=n;i++){
    printf("node %d: key = %d, ",i,Array[i]);
    if((i/2)>=1)printf("parent key = %d, ",Array[i/2]);
    if((i*2)<=n)printf("left key = %d, ",Array[i*2]);
    if((i*2+1)<=n)printf("right key = %d, ",Array[i*2+1]);
    printf("\n");
  }
  return 0;
}
    

