#include <stdio.h>
int main(){
  int H,i,A[251];

 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(2*i >0 && 2*i<=H)    printf("left key = %d, ",A[2*i]);
 
    if(2*i+1>1 && 2*i+1 <=H)    printf("right key = %d, ",A[2*i+1]);
     
    printf("\n");
  }
 

  return 0;
}