Counting values

Hey i want to make a pillar diagram

this is the values:
X: weight = 1 amaunt = 4
X: weight = 2 amaunt = 2
X: weight = 3 amaunt = 4
X: weight = 4 amaunt = 2
X: weight = 5 amaunt = 4
X: weight = 4 amaunt = 2
X: weight = 3 amaunt = 4
X: weight = 2 amaunt = 2
X: weight = 1 amaunt = 2

Now i want to sort it so that the weight is horizontal, and stack if there are to of the same weight.
1. pillar named 1 with a value of 6 (4+2)
2. pillar named 2 with a value of 4 (2+2)
3. pillar named 3 with a value of 8 (4+4)
4. pillar named 4 with a value of 4 (2+2)
5. pillar named 5 with a value of 4 (4)
and if i was to change anything it would correct it self.