include<stdio.h>
#define MAX 100000
 
int parent(int);
int left(int);
int right(int);
 
int main(){
  int H,i,A[MAX+1];
 
  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(parent(i)>=1){
      printf("parent key = %d, ",A[parent(i)]);
    }
    if(left(i)<=h){
      printf("left key = %d, ",A[left(i)]); 
    }
    if(right(i)<=H){
      printf("right key = %d, ",A[right(i)]);
    }
   
  }
 printf("\n")
  return 0;
}
 
int parent(int x){
  return x/2;
}
 
int left(int x){
  return 2*x;
}
 
int right(int x){
  return 2*x+1;
}