# Pastebin 11FrLMyJ
import sys
import gc
import weakref

class A:
    pass

def other(a):
    v = []  # using a list rather than nonlocal for pypy2 support

    # delete the only remaining ref to a and replace with a weakref
    a = weakref.ref(a, lambda _: v.append(True))
    while not v:
        # on cpython this branch is never hit, but on pypy we need to sit and
        # collect, until the object is deleted
        gc.collect()


def main():
    # move our reference to the instance of A into other
    other(*(A(), ))

if __name__ == "__main__":
    sys.exit(main())