#include<stdio.h>
#define MAX 251
int main(){
  int A[MAX],n,i;
  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>0) 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;
}