#include<stdio.h>

int H[251];





int main(){
	int i,n;	scanf("%d",&n);
	for(i=1;i<=n;i++){
		scanf("%d",&H[i]);
	}




	for(i=1;i<=n;i++){
		printf("node %d: key = %d, ",i,H[i]);
		if(i/2>=1)printf("parent key = %d, ",H[i/2]);
		if(i*2<=n)printf("left key = %d, ",H[i*2]);
		if(i*2+1<=n)printf("right key = %d, ",H[i*2+1]);

		printf("\n");
	}

	return 0;
}


