#include <stdio.h>
#define MAX 10000
int parent(int i) {return i/2;}

int left(int i){return 2*i;}

int right(int i) {  return 2*i + 1;}

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