#include <stdio.h>
#include <math.h>
#define N 250

int parent(int i){
    return floor(i/2);
}

int left(int i){
    return 2*i;
}

int right(int i){
    return (2*i)+1;
}

int main(){
    int n,A[N],i;
    scanf("%d",&n);
    for(i = 1;i <= n;i++){
        scanf("%d",&A[i]);
    }
    for(i = 1;i <= n;i++){
        printf("node %d: key = ",i);
        printf("%d, ",A[i]);
        if(i != 1){
                printf("parent key = %d, ",A[parent(i)]);
        }
        if(left(i)<=n){
             printf("left key = %d, ",A[left(i)]);
        }
       if(right(i)<=n){
        printf("right key = %d, ",A[right(i)]);
       }
    
        printf("\n");
    }

 return 0;
}
