#include<bits/stdc++.h> #define int long long using namespace std; double x,y,c; int ch(double z){ double a=sqrt(x*x-z*z),b=sqrt(y*y-z*z); if(a*b>=c*(a+b)) return 0; return 1; } signed main(){ while(cin>>x>>y>>c){ double l=0,r=min(x,y); while(l<=r){ double mid=(l+r)/2.0; if(ch(mid)==0) l=mid+1e-4; else r=mid-1e-4; } cout<<fixed<<setprecision(3)<<l<<"\n"; } return 0; }