#include<stdio.h>
#define N 250

int main(){
  int size,i,key[N];

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

