include

include

using namespace std; int main(void){

//freopen("1106.in","r",stdin);
//freopen("1106.out","w",stdout);
int a,b,c;
scanf("%d %d %d",&a,&b,&c);
a/=10;
b=b*10+c;
printf("%.2lf",(double)a/b);
return 0;

}