#include <stdio.h>

int main(){
  int i,h,key[251];
  
  scanf("%d",&h);
  for(i=1;i<=h;i++){
    scanf("%d",&key[i]);
  }
  for(i=1;i<=h;i++){
    printf("node %d: key = %d, ",i,key[i]);
    
    if(i!=1)  printf("parent key = %d, ",key[i/2]);
    if(i*2<=h) printf("left key = %d, ",key[i*2]);
    if(i*2+1<=h)  printf("right key = %d, ",key[i*2+1]);
    
    printf("\n");
  }
  return 0;
}

