#include <stdio.h>
#define MAX 100000

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

