// https://omegaup.com/arena/problem/Evaluando-una-formula-con-potenc 
#include <stdio.h> 
#include <math.h> 
 
int main( ) { 
   float x, y, z; 
   scanf("%f%f%f", &x, &y, &z); 
   float t = 2 * x + y - z; 
   float num = 7 + pow(t, t); 
   float den = t; 
   printf("%f", num / den); 
   return 0; 
}