type Foo = string 
type Foo2 = string

fn (f Foo) + (f1 Foo2) Foo2 {
    return Foo2(f + f1)
}

fn (f Foo) * (f1 Foo) Foo {
    return Foo(f + f1)
}

fn main() {
   mut f := Foo('fg')
   f += 'fg'
   f *= Foo2('2')
   f -= Foo('fo') 
    println(f)
}