#include<stdio.h>
#define MAX 100000



int main(){
  int H,i,A[MAX+1];
  /* parent=i/2;
  left=2*i;
  right=2*i+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(i/2 >= 1)printf("parent key = %d,",A[i/2]);
    if(2*i <= H)printf("left key = %d,",A[2*i]);
    if(2*i+1 <= H)printf("right key = %d,",A[2*i+1]);
    printf("\n");
  }
  return 0;
}