#include<stdio.h>
#define MAX 100000

int parent(int i){
return i/2;
}

int left(int i){
return 2*i;
}

int right(int i){
return 2*i+1;
}

int main(void){

int n,i,A[MAX+1];
	
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(parent(i)>=1){
printf("parent key = %d, ",A[parent(i)]);
}
if(left(i)<=n){
printf("left key = %d, ",A[left(i)]);
}
if(right(i)<=n){
printf("right key = %d, ",A[right(i)]);
}
printf("?\n");
}

return 0;
}