#include<stdio.h>
#define MAX 1000000

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

int main(){
  int n,i,A[MAX+1];

  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)]);

    printf("\n");
  }

  return 0;
}