How many denominations of stamps do I need to send a letter from Guangdong to Beijing?

Within the first weight100g, 0.80 (local port) 1.20 (foreign port) for each 20g (less than 20g is calculated as 20g).

Continued weight 10 1-2000g, each weight 100g (if less than 100g is calculated as 100g) 1.20 (local port) 2.00 (foreign port).

To put it simply, within100g, each 20g of 0.8 yuan outside the city is 1.2 yuan.

Over 100g,1.Every city outside 2 yuan 100g 2 yuan.