#include<stdio.h>

int main(){
    int i,H;
    int A[250+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;
}
