#include<stdio.h>
#define MAX 1000

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

