#include<stdio.h>

int main (){
  int H,i,A[500];
  
  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/2 > 0) printf("parent key = %d, ",A[i/2]);
    if(i*2 <= H) printf("left key = %d, ",A[i*2]);
    if(i*2 + 1 <= H) printf("right key = %d, ",A[i*2+1]);
    printf("\n");
  }
  
  return 0;
}

