int max3(int a,int b, int c)
{
if (a > b && a > c)
return (double*)a;
if (b > a && b > c)
return (double*)b;
if (c > b && c > a)
return (double*)c;
//或者方法二:return a>b? a>c?a:c : b>c?b:c;
}
int main()
{
int a = 0;
int b = 0;
int c = 0;
double m = 0;
scanf_s("%d%d%d", &a, &b, &c);
int ret=max3(a + b, b, c);
int hhh=max3(a , b+c, c);
int fff=max3(a , b, b+c);
m = 1.0*ret / (hhh + fff);
printf("%.2lf", m);
return 0;
}