#include <stdio.h>
#define N 251

int parent(int );
int left(int );
int right(int );

int main(){
    int i,n;
    int A[N];

    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;
}

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

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

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