#include<stdio.h>

#define H 250

int main(void){
  int i,size;
  int A[H];
  scanf("%d",&size);
  
  for(i=1;i<size+1;i++) scanf("%d",&A[i]);

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

  return 0;
}