#include <stdio.h>
#define HMAX 251
int main(){

	int i,H;
	int A[HMAX];

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


	return 0;
}