#include<stdio.h>
#define max 100000
int parent(int i){
return i/2;
}
int leftnode(int i){return 2*i;}
int rightnode(int i){return 2*i+1;}

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

