#include <stdio.h>

int main()
{
  int i,n,A[1000000];

  scanf("%d",&n);
  for(i=1;i<=n;i++){
    scanf("%d",&A[i]);
  }

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

