#include<stdio.h> int max3(int x,int y,int z) { int max; if(x>=y) { max = x; } else max = y; if(z>=max) { max=z; } return max; } int main() { int a,b,c; scanf("%d%d%d",&a,&b,&c); printf("%.2f",(1.0*max3(a+b,b,c))/((max3(a,b+c,c)+max3(a,b,b+c)))); return 0; }