
#include<stdio.h>
#include<math.h>

int parent(int i){
  return i/2;
}
int left(int i){
  return 2*i;
}
int right(int i){
  return 2*i+1;
}

int main(){
  int n;
  int i;
  int A[250];

  scanf("%d",&n);
  for(i=1;i<=n;i++){
    scanf("%d",&A[i]);
  }

  for(i=1;i<=n;i++){
    printf("node %d: key = %d, ",i,A[i]);
    if(parent(i) >= 1)printf("parent key = %d, ",A[parent(i)]);
    if(left(i) <= n)printf("left key = %d, ",A[left(i)]);
    if(right(i) <= n)printf("right key = %d,",A[right(i)]);
    puts("");
  }

  return 0;
}