#include <stdio.h>

#define H 250
int main(){
  int A[H];
  int i,n;


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 != 1) printf("parent key = %d, ",A[i/2]);
if(2*i <= n) printf("left key = %d, ",A[2*i]);
if(2*i+1 <= n) printf("right key = %d, ",A[2*i+1]);
printf("\n");
}
return 0;
}