#include<stdio.h>
#define MAX 100000
main(){
  int n, i;
  int A[MAX+1];
  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(i*2<=n)printf("left key = %d, ",A[i*2]);
    if (i*2+1<=n)printf("right key = %d, ",A[i*2+1]);
    printf("\n");
  }
   return 0;
}

