#include <stdio.h>

int main(){
  int i,H,A[100000];

  scanf("%d",&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(1<=i/2) 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;
}