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