#include <stdio.h>
#define M 100000

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

int main(){
    int i,n,A[M+1];

    scanf("%d",&n);
    for(i=1;i<=n;i++){
        scanf("%d",&A[i]);
    }
     for(i=1;i<=n;i++){
         printf("node %d: key = %d, ",i,A[i]);
         if(parent(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;
}

