#include<stdio.h>

int main(){
  int H,i,A[100000];
  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>=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;
}

