#include<stdio.h>


int main(){

  int i,H,A[250];  

  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){
     if(i % 2 == 0){
       printf("parent key = %d, ",A[i/2]);
       }
     else{
       printf("parent key = %d, ",A[(i-1)/2]);
	 } 
   }

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

