#include<stdio.h>
#include<stdlib.h>
 
#define MAX 251
//#define NIL -1
 
int main(void){
  int i,n,left,right;
  int A[MAX];
 
  scanf("%d", &n);
  for(i=1; i<n+1; i++) scanf("%d", &A[i]);
 
  for(i=1; i<n+1; i++){
    printf("node %d: key = %d, ", i, A[i]);
    if(i/2 != 0) printf("parent key = %d, ", A[i/2]);
    if(i*2 <= n) printf("left key = %d, ", A[i*2]);
    if(i*2+1 <= n) printf("right key = %d, ", A[i*2+1]);
    printf("\n");
  }
 
  return 0;
}