Need to Exit But have double entry ..so where I can go ? Any other country or ? Iam from Pakistan ..

I am from Pakistan .i have M type with double entry ,each stay 30 days .i have to exit after 4 days and have to renter in china so can I go to Hongkong for exit , like just get at airport and come back after one hour or I must have to go a country where we Pakistanis can get free entry or VOA? So I am confused about it ..help me out ..another thing I want to know that which visa easily I can get for one year with multiple entries expect Z and X , like I can stay minimum 90 days once I enter in china ..thanks a lot ..plz help me out if someone knows about it ...