#include<stdio.h>
int main(){
  int i,n,A[250];


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


  for(i=1;i<n+1;i++){
    printf("node %d: key = %d,",i,A[i]);
    if(i != 1){
      printf(" parent key = %d",A[i/2]);
    }
      if(2*i <= n){
	printf(" left key = %d",A[i*2]);
      }
      if(2*i+1 <= n){
	printf(" right key = %d",A[i*2+1]);
      }
    printf("\n");
  }
 
  return 0;
}