#include<cstdio>
int main()
{
	while(1)
	{
	    double T=6,t,sum=0,max=0,min=999;
	    while(T--)
	    {
			scanf("%lf",&t);
		        sum+=t;
			if(t<min)min=t;
			if(t>max)max=t;
	    }
		if(sum==0)break;
		printf("%g\n",(sum-max-min)/4.0);
	}
	return 0;
}