#include<stdio.h>
#include<stdlib.h>
#include<math.h>


void main()
{
	int n,k=0,age,X;
	scanf("%d",&n);
	while(1)
	{
		scanf("%d",&age);
		if(age>=15){
		X=age-7;
		printf("%d\n",X);}
		else {X=-1;
		printf("%d\n",X);}
		k++;
		if(k==n)break;
	}
}