#include<stdio.h>
#define MAX 100000

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

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

