HU SNG

[dw33b]

So I sit down at a HU SNG and my opponent proceeds to push every hand. If I limp when I'm the button, they push. I'm not sure how to figure out the math on this problem. I don't want to call with any cards better than a random range because I know the future action. What do you think I have to call with????

Just for clarification, 1500 stacks to start and 10/20 blinds.