#include <stdio.h>
#define h_max 251

int H;
int A[h_max];

int main(){
  int i,j;
  
  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/2 > 0){
      printf("parent key = %d, ",A[i/2]);
    }
    
    if(i*2 <= H){
      printf("left key = %d, ",A[i*2]);
    }
    
    if(i*2+1 <= H){
      printf("right key = %d, ",A[i*2+1]);
    }
    
    printf("\n");
  }
  return 0;
}

