#include <stdio.h>

#define H 251

int A[H];

int main(){

int i,n;

scanf("%d",&n);
for(i = 0 ; i < n+1 ; i++)A[i] = -1;//?????????

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(i/2 <= n)printf("parent key = %d, ",A[i/2]);
if(2*i<= n)printf("left key = %d, ",A[2*i]);
if(2*i+1<= n)printf("right key = %d, ",A[2*i+1]);
printf("\n");

}

return 0;
}