values = [8, 3, 1]
group = {2, 7} 
def f(values, group):
    count = 0
    def g(x):
        nonlocal count
        if x in group:
            count += 1  
            return (0, x)
        return(1, x)
    values.sort(key=g)
    return count 
count = f(values, group)
print(count)