#include <stdio.h>
#define MAX 100000

int parent(int);

int left(int);

int right(int);

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(parent(i) >= 1){
        printf("parent key = %d, ",A[parent(i)]);
    }
    if(left(i) <= H){printf("left key = %d, ",A[left(i)]);}
    if(right(i) <= H){printf("right key = %d, ",A[right(i)]);}
    printf("\n");
    }
    
    return 0;
}
int parent(int i){
    return i/2;
}
int left(int i){
    return 2 * i;
}
int right(int i){
    return 2 * i + 1;
}
