#include<stdio.h>
int main (){
  int n,i;
  int A[100001];
  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;
}



