#include<stdio.h>
#define N 250

int main(){
  int i, H, A[N-1];

  scanf("%d", &H);
  for(i = 0; i < H; i++)scanf("%d", &A[i+1]);

  for(i = 1; i <= H; i++){
    printf("node %d: key = %d, ", i, A[i]);
    if(i != 1)printf("parent key = %d, ", A[i/2]);
    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;
}

