#include<stdio.h>
#define MAX 100000

int main(){
int H,i,A[MAX+1];

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/2>=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;
}