
#include <stdio.h>
#include <stdlib.h>

int parent(int i){
  return i/2;
}

int main(){
  int h,i,A[250];
  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[parent(i)]);
    if(i*2<=h) printf(" left key = %d,",A[2*i]);
    if(2*i+1<=h) printf(" right key = %d,",A[2*i+1]);
    printf("\n");
  }
  return 0;
}