#include<stdio.h>

int main(){
  int n,i,key[250];
  scanf("%d",&n);
  for(i=1;i<=n;i++)scanf("%d",&key[i]);
  
  for(i=1;i<=n;i++){
    printf("node %d: key = %d, ",i,key[i]);
    if(i/2 >= 1)printf("parent key = %d, ",key[i/2]);
    if(2*i<=n) printf("left key = %d, ",key[i*2]);
    if(2*i+1<=n)printf("right key = %d, ",key[i*2+1]);
    printf("\n");
  }
  return 0;
}

