#include <stdio.h>

int main()
 {
   int a,b,c;
   scanf("%d %d %d",&a,&b,&c);
   int S = 0;
   S = (float)a * 0.2 + (float)b * 0.3 + (float)c * 0.5;
   printf("%d",S);
    
    return 0;
}