#include <stdio.h>

int a[1030];
int main(){
	int n;
	scanf("%d",&n);
	for(int i=1;i<=n;i++)scanf("%d",a+i);
	for(int i=1;i<=n;i++){
		printf("node %d: key = %d, ",i,a[i]);
		if(i!=1)printf("parent key = %d, ",a[i/2]);
		if(i*2<=n)printf("left key = %d, ",a[2*i]);
		if(i*2+1<=n)printf("right key = %d, ",a[2*i+1]);
		puts("");
	}
}
