#include <stdio.h>
int main(){
  int i,H,A[251];
  scanf("%d\n",&H);
  for(i=1;i<=H;i++)scanf("%d",&A[i]);
  for(i=1;i<=H;i++){
    printf("node %d: key = %d, ",i,A[i]);
    if(i/2>=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;
}


