#include <iostream>
using namespace std;
int main()
{
int a=5;
double b=-3.5;
double s=a+b;
s = 2*s-b;
cout << s;
return 0;
}
#include <iostream>
using namespace std;
int main()
{
int a=5;
double b=-3.5;
double s=a+b;
s = 2*s-b;
cout << s;
return 0;
}